Considering a 111r purchase

[kambites]

If you don't have a garage, air con is a significant bonus. If you do, I wouldn't (and didn't) bother.

[Beachbum]

rog007 said:

It's really for demisting in the winter which I've read can be an issue without it?

As long as the Heater Blower works, you will be fine, or at least I have always been. AC will speed it up, but we arent talking more than a couple of mins for the Blower to do the job, without AC.
If you end up looking at an Exige, then AC is a must. I am surprised it was never considered standard equipment by Lotus, but the extra weight may have put some people off.