I went from a clio to sti. You HAVE to make sure it's a good one or you'll be parting with a lot of cash. I use it as an everyday car as I did with my clio. Funding wise, I'd say costing has gone up x3. Will be in the thousands for a major repair. Insurance is steep if your young or/and have points and claims etc. Sure you can get high 20's low 30's mpg if you drive conservatively but come on, you wouldn't even consider buying this car if that was the case.
The clio was indeed a very worthy car. Very nimble and one of the best handling hatchbacks out there. Price-wise, I honestly don't believe there's anything that can match it. But - when you're talking awd turbo'd saloon vs fwd naturally aspirated hatchback; it's a whole different ball game. What would cost £1k on the clio could get you I dunno - 10+ bhp? where the same spent on a sti esp. a jdm would get you 50+ bhp. We're talking just exhaust system and re-map from a highly praised mapper such as JGM, Andy forest etc. Few more mods at around the same cost if you're lucky will see you get the same increase again.
If you decide to go for one - just make sure you have enough funds to back you up if anything goes wrong....buying one of these will put a very big smile on your face