Get to a full on stage 2, do some track time and some mega drives, then decide if you're happy or really want more. Consider the outlay also = £10k+ for a mega BT setup done to a top standard.
Too many people in the past have thought they need 'x' bhp to have a good Leon and forget the overall package... Pub talkers and the like IMO..
I'm loving my car more than ever now all departments have been covered to make it an all rounder. I can lose my license easily if I'm not careful, and this is only stage 2. Just really think it through. It's a load of money to go BT, some are epic in the end (James L's, which is my favourite as no expense has been spared in all departments, as it should be when you're chasing 500bhp)
You may decide you want something else entirely that would take the power better like an Evo or similar in the end. Just my 2p's worth.
I will be keeping my Leon for years yet. I know stage 2 cars well maintained lasting well into high mileage and I'm around 65k on mine now so plenty of life yet, and the most important thing is it makes me happy as anything on a good drive.