I have a base model 07 Eos (and I don't give a crap if people think its a chick car). To answer some questions:
1) Never had a major leak issue. However, as with all cars with frameless windows, careful how you point that pressure washer when cleaning (too close or at the wrong angle will force water into the car. Also, the seals must be maintained with Krytox. VWVortex Eos forum has tons of info, for those that are interested.
2) It is somewhat noisy in the winter, but expected considering its a convertible.
My purchase decision was simple - it is the best value out of the 4 seater, hardtop convertibles. The G6 has no cargo space with the top down and the front windscreen/windshield you have avoid when entering the car, and it's almost the same price. The redesigned Sebring wasn't out yet, but I don't like their styling or pricing, regardless.
Buying in the US presents some warranty problems and with 470 parts in the roof alone, the warranty is something I did want, considering I purchased it in the first year of production.
As for annoyances, I hate how VW packages their options. My base Eos doesn't have steering wheel controls or a trip computer. I don't care that it's base - the car was over 40K (w/ tax, etc.) and I expect at least that for equipment in general. It's annoying how I need to get the entire package of stuff (at 4K) in order to get those basics with stuff I don't want.
Otherwise, dropping the top at anytime and driving puts a grin on my face.
And no, -15C isn't too cold. LOL
PS: For those wondering what a base interior looks like, I have pics in the Show and Shine forum. I know for me here in Alberta, base models are rare - so you don't even get to see what you're buying generally. Dealers tend to carry the loaded model.