Love the 4*.
My take on it all after 20+ years and several long periods away from the hobby.
Low wing with light wing loading and mostly symetrical airfoil is simply a ball to fly, and once you understand the mechanics of flight on a trainer
are a great way to progress rapidly.
Moving to anything else as an intermediate is really not necessary in my opinion.
After a 5 or so year off time I used a brand new 4*60 for my "check flight" at the local club I joined and was like riding a bike.
Smooth, predictable and a ball to fly.

I strongly second the "build your own". I fly lots of ARF, but I still have built enough to understand how all the bits go together