Saving presets is the least it can do.. Though, If a preset already has a Reverb in it, then you'll only have an option to add a second, I think..
High quality cabs, reverbs, and effects like drives will lean-heavily on the CPU. Knowing that, there Are ways to free-up CPU if necessary - by lowering the quality of cabs and reverbs (etc.) and removing drives which aren't being utilized in scenes and moving them into channels, etc..
Which ..all sounds like word-soup to you right now, maybe.. :0)
Definitely spend time with the manual. It's a dry read, but it's a lot of machine and you only have to read that manual once - having said that, it IS a remarkably easy machine to learn and you can quickly get your head around all it can do when you know what all those options will basically do.. Unfortunately, there's no real substitute for going through the manual to more quickly learn those options.
..once you get your head around 'scenes', you'll wonder how you ever lived without them. :0) ..took me a while to get my head around all this thing will do.. I'm an old-school stomp-box guy, too. But, once you learn how to use this thing, in most all respects, it's just a much better system..
..Needs more knobs I can twiddle.. Needs more knobs! Programmable knobs for drive - amp controls - delay, m'be.. a separate rack-space USB linked control unit!!! with programmable knobs on I can twiddle..
...That's what it needs! ...
**sigh ..ain't nuthin' perfect is it! :0)
Yeah-yeah-yeah... "Opinions" -blah-blah-blah.. :0)
But.. Even lacking more knobs.. It's still pretty-good! :0)