I think I will have to reserve my views on this untill after the final release of vista to give a full opinion... However
Tiger - Everything somehow seems very smooth in tiger just from a 'how it looks' point of view. Never been quite too keen on the one mouse button thing they have on the mac (I like my right mouse button). The only thing for me that has ever made the mac special is the fact that it tends to run faster, however now its using intel chips I really dont think thats the case anymore... I can see it dying of death eventually.
Vista - Massive improvement over windows xp graphically, and although people may say it looks like mac, if the mac looks right, then so it should. Only downfall I can see is that it will inevitably impact performance which at the end of the day should be any computer users number 1 concern. But as I said, I will reserve judgement too much on this one till it comes out as a final product. (Have to say I like the dynamic folders though)
OHHHHHH .. and since this is my first post ...... ello