Here's the thing - the "performance loss" you suffer with Wine is generally not losing speed or whatever. It happens sometimes, but it's not the main problem. Where you really run into problems is when stuff just plain doesn't work at all, or crashes a lot, or certain features don't work etc. So it doesn't really make sense to ask whether the performance loss from Wine will be compensated for by Ubuntu. No, it won't, because the kind of performance loss you're really gonna notice isn't a processing speed thing. On the flipside, you may be able to run many applications with performance as good as (or even, theoretically, better than - but this rarely happens) Windows.
Another major issue - graphics support in Linux just isn't as nice as it is in Windows, at least not yet. You can get proprietary graphics drivers with 3D acceleration and whatnot, but you will likely see reduced performance with equivalent hardware. So if you're worried about gaming, well, you should be.
That said, you might in fact see improved performance in terms of, say, memory management. Plus there'll probably just be a bit more of it free anyway. And the server will work quite well. Just know that switching to Linux for the purpose of, say, getting your games to run faster is a bad idea. It makes more sense to do so for other benefits, such as security and customizability.
Oh, and as Keltari commented, do check that the applications you're worried about are compatible. You can search for them on Wine's application database. If you're willing to do a bit of tweaking odds are actually pretty good you can get major applications working.