One of the biggest changes in our sport at the higher levels since I started playing in the late 1970s is the development of what I call the "topspinny backhand." (I should trademark that term.) When I started, most players had relatively flat backhands, with only a little topspin. The idea was to hit or block aggressively. A few players backed up and backhand looped, but few players played close to the table and tried to topspin heavily with their backhands. Part of this was the equipment - modern sponges are much bouncier and better for this.
At first glance, a good, hard, flat backhand is a better shot. After all, it tends to come out faster, and it's easier to time, as opposed to trying to take a bigger swing and spin the ball off the bounce. There were many big backhand hitters and great blockers back in those days, but only a few really spun their backhands off the bounce over and over. (Tibor Klampar and Anton Stipancic are two that did.)
These days nearly everyone at the higher levels topspins off the bounce. There's a terminology problem - it's not quite a backhand loop (usually), but it's more than a regular backhand. Hence my term, "topspinny backhand."
What are the advantages of these topspinny backhands?
One of the tougher questions for coaches is when to start players with topspinny backhands. Some say around 1800 (roughly advanced intermediate level). Others teach it almost from the start. I've seen it successfully learned both ways. But it does help to develop this shot somewhat early or you may get ingrained in your habits. I developed a flatter backhand early in my development, and while I can demonstrate a topspinny backhand, I'd have to spend a lot of practice time if I wanted to incorporate it into my game - and there's no guarantee that I'd be able to do so successfully after 37 years of flat backhands.
It's your choice - go flat or go topspinny!