Greetings...
Right now - 2019, we are at the point where the R4 and new R5 are actually MORE computer than ANY game on the market even come close to.
There is currently, simply, no need for anything more 'powerful'. Unless you have some weird desire to run multiple monitors, and other such wallet sucking uselessness.
I've had my R4 for about 2 years now, and I've never found any game or other app that I can't run perfectly at full graphics and whatnots.
I expect this thing to be just fine for at least the next 5 years (or until games catch up!). In the past, I've noticed a discernible slowdown when I run multiple copies of an on-line game (multiple chars simultaneously) or when having a number of apps open at once. Not so with my R4! I haven't noticed any kind of slowdown and yeah, there are times when I really try to bog it down, just to see if I can. Only time I've come close is during the summer, when it gets hot! But that's a Thermal issue, not a performance issue. As long as you keep it cool, the R4 is likely more 'puter than most mortals will ever need. (it's a gaming machine!)