I have built 3 kits in the last couple years.... A 372, one 660, and one 440 clone.
All where decent runners, and the 372 still runs ok. New, they keep up with the real deal as far as speed of cutting is concerned, but sacrifice the reliability or the original.
These are not as high quality parts as a new stihl or husqvarna saw, and require a decent amount of time and effort to keep running.
I have since bought a new 661, and a couple original 372's which are stellar saws and run very well with far less headache.
I picked up 2 well used, but functional and so far reliable 372's for the cost of one pre-built kit saw. Worth a look into that option IMO. The kits are reasonably easy to build, and I find it fun.
I had a 9 year old helping me with mine and we had a blast. We both learned a lot, which was completely worth it. (I do jokingly blame her for the reliability concerns sometimes... lol)
I don't have any experience with pre-built saws.