My opinion might be slightly biased here
GTTs are great fun, like little go-karts, thrash them around and they take the abuse, i had my first one 8 years, never blew a head gasket once, bent a valve through my own fault and a couple of gearboxes but not bad considering it had done 130k and still on the original turbo when it was stolen.
As with any car if you look after them they will last, regular oil changes, too many people wack a bleed valve on wind the boost up and think its goign to take it, wrong if you wind it up everything else has to be uprated as well, a standard head gasket wont take it, so as long as youre not silly it will last.
Once youve had a turbo car though there is no going back you get used to the kick of a turbo and miss it then just have to go and but another turbo.
I dont know that much about the clio, apart from its very compact, its a 19 16v engine basically in a smaller space. (I have an engine spare if anyone needs one btw !) They are newer and the shape is more streamlined.
Having two cars is an ideal situation. How about ytou test drive both and see what you think. Check out
http://www.rtoc.orgwww.rtoc.org if you want info on a gtt there is also a buyign guide on there of what to look out for.