I use it in Windows ME, but have just had a quick look at it a few times. It seems very impressive, and if other Serif software is anything to go by you won't be disappointed. Only thing you have to deal with is a bit of advertising for other Serif products, which one can hardly gripe about. They have to make some money somewhere.
One serious omission seems to be the lack of WMF import. However, if you can open metafiles in another application you can paste them into Drawplus via the Paste Special menu. I tested this from Corel Draw and it seemed to work fine.