It depends on what you'd like for it to do. Just about any of them will take you from A to B. Some of the newer ones will guide you to the faster lanes, but those would be in the $300 range. That's what I would get. Garmin, Magellan are your top of the food chain.
Marketshare in the US
#1 Garmin (50-60%)
#2 TomTom (20-25%)
#3 Magellan (10-12%)
#4 Mio (5-6%)
New Garmin and TomTom models are being released in the next 30 days. Good chance you'll see older models being discounted (like TomTom 125 for $99 or less at Walmart) in May.
Magellan is using new software (a version of Nav N Go) on their higher end models and just announced some new hardware - very sleek and thin.
I recommend going with a larger screen, like 4.3". It's much easier to see and use (buttons are larger on the touch screen).
Traffic is nice, but will only work in major metro areas. Some now will get fuel prices, which is pretty cool. Bluetooth is over rated in my book.
Personally, handset solutions are still inadequate for real navigation and guidance. There's latency issues and the screen is small and the speaker isn't loud enough for clear audio instructions. Of course things will change, but today the PND (Portable Nav Device) is still the better solution.
I have three Garmins, and I really like all of them. I haven't tried other brands but Garmin has excelled beyond my expectations so I'm loyal to them.
My first was the cheapest Nuvi, I think the model number was 200, and it was excellent. The two extra features I now find useful are the built-in bluetooth speakerphone for cell phones, and the very indulgent text-to-speech which says road names--"Turn at Oak Street" rather than "Turn in 500-feet".
I always found the Garmin website to be useless for comparative shopping (maybe it's changed now), however Amazon has nice charts for simple comparisons, like this one:
I like my cheap Tom Tom One. It does the basics (navigate you to the right place), locks up to the satellites faster then my friend's Garmin and small enough to fit in my pocket so I don't have to worry about people stealing it out of my car. Also, you can download a (user created) Elise or Exige icon for your car. :shift:I really don't need any of the other fancy features that are on the more expensive models.
Have used Garmin, but no others. Bought a NUVI last year, forget the number. I still have not found out all it can do. My wife bought it and for what she paid at the time, I think it has a follow you the the restroom and wipe for you mode!!! At least it should. The prices are droping fast on them though.
I'm starting to look for a better GPS than my current one. Here's my tentative feature wish list:
Good brand (e.g., Garmin, xxx
Speaks street names on which to turn
Traffic alerts & detours to minimize driving time
Map content updates from content provider to getter updates sooner (i.e., NavTeq, not the GPS manufacturer’s web site)
Ability to download contacts from Outlook or integrate with my Blackberry so I don’t have to type in address, I can just select from the list of contacts I already have
Ability to enter or upload Points of Interest myself.
Ability to search for a Point of Interest “along my route” rather than near my current location or near my destination
Something to consider: cost of map updates and cost of traffic report subscription
Since you say it's for a road trip and you're going in May, you won't have enough time to really learn all the ins and outs.
There are some terrific new ones out or soon out that have Voice recognition (for input),,,but that may be over the top for your purposes. At a min, do not get anything without Text to speech (spoken street names). A 4.3 display is extremely nice if you look up a lot of nearby points of interest. Map dates are also key--they cheapies (and I just bought another (#12 or 13?) last week) --the cheap ones will have map datum 2 to 3 years old. Even the Garmins and TomTom try and pawn off 2 year old data with some current models--discounting them slightly adn then throwing in a coupon so that you can buy a current set for THE SPECIAL LOW PRICE of $50 or some such---which is a total ripoff...BUT, the point is moot if you are going on interstates and to well established/larger cities (they don't change much over time).
Live traffic update options are nice, but then buy one with a lifetime subscr, not a mo-to-mo subsc.--it's not foolproof---traffic updates are instant. LAg time means you could just as well get stuck as not. MSN service is nice also, but not at all necessary for routing.
Most of the GPS hardware is pretty comparable nowadays (even a lot of the Mio's and other lower priced options use current/nearly current chip sets. The key is SOFTWARE (not maps--whcih all come from 2 companies)--its' how the device operates ---how does do it's routing, how does it allow for searches, how does it handle re-routing, and so forth. Trouble is, you really need to try 2 or 3 for a few days to appreciate the differences. Garmins are nice--I have 4. I also have mios, Navigons, and a Pharos and used TomTOm extensively. For an extra 40-50, I'd go with the Garmin (or TomTOm)...but they still prem price their better gear--and compared (on feature set) to the top line Mios and such, it doesn't justify it.
...aghhhh. Forgot one KEY point. Don't get any GPS that doesn't allow you to enter or import a list of RED LIGHT camera locations. These @#%$%^ things are like weeds in the Chicago area. The GPS starts chirping as I approach the ones I've entered. These RL cams SPECIALIZE is separating the avg driver from $100 /per offense)---some installs are 100% generating on those that stop AFTER the painted white line for a right-on-red.
I have a TomTom XL Europe Traffic, which is my third TomTom. Where I live, TomTom has by far the best maps so there's not much choice. (Last I checked, the Garmin only had main city maps for Eastern Europe).
This is a big improvement over previous TomTom models for 2 reasons:
1. The suction mount never falls off since you "screw" it to the windshield. (You then "unscrew" it to remove it)
2. Because the mount folds easily onto the unit, it's easy to remove the unit and the suction mount and take it with you (or hide it) so there's no signs you car has a GPS in it. Just leaving the suction mount (without the unit) on the windshield can attract thieves, as I found out the hard way with a mount on my other car
I can't really comment on whether it's better or worse than other brands at navigation or getting the GPS signal, but probably you can find a lot of reviews online about those details.
I'm picking up a Garmin Zumo, which is designed for motorcycles, but very versatile. I want to use it on my bikes and in the Elise. Water resistant (perfect for the Elise!) and designed for easy use at speed. New 600 model just released.
Does the newer GPS allow you to enter coordinates instead of an address because I know most old ones don't? I find this to be the best feature in my Mio. A lot of times its database does not contain the address that I type in and I can just look up the coordinates and punch it in. Sometimes when you have a car following you and it got separated, you can just pull over and call and give the other car your coordinates. I can't understand why most other GPS will not allow you to enter coordinates. Its a GPS for god sake.