yea, engine wise the car will still be reliable and runs as smooth as stock with a good tune. However if you do get air filter, boost controller and sti tmic or maybe injectors, you'll be able to make full use of the vf34, hence more boost, torque and power, but at the same time, you'll most likely be looking at a new clutch as well as your stock one will slip. Then you'll be worrying about your gearbox.

However if thats far too much mods than you had expected then you probably shouldn't get a vf34. Afterall there is no real significant gain in running stock boost in a vf34 and without the supporting mods too. Even tho its a ball bearing turbo, it is a larger turbo, hence it should still be laggier than the tiny stock turbo.