Lotus by far. The minor drawbacks are far outweighed by the advantages.
Get a Lotus and leave some cash spare for a "hackmobile" that you can take to dodgy places and lug bags of cement in...
The MX-5 is good but it's boring to look at and you certainly won't be terribly bothered about keeping it clean. With a Lotus you will practically have another family member...
MX-5 is slow too. And a powered hard top is heavy.