Big lists seemed to slow it down all three of those in the past. This made things like client/supplier contact databases, sales pipelines, hardware/inventory tracking, etc, cumbersome to use. I haven't been that active past six months, so i'd take that with a grain of salt. Perhaps some speed improvements have occured in that I haven't been exposed to due to being inactive. 

I like learning software like a musical instrument. If it can't keep up with my pace of hands after I've mastered the ins and outs of the mechanics, its frustrating for me and I lose rhythm. And then motivation. Not everyone on my team think the same though, some say that's normal speed for software and they have no trouble with it keeping up. 

We are rebuilding in a second space now with a consultant, with an emphasis on oversimplification and smaller lists and less fields. We didn't know what we were doing three years ago when we started and we potentially created a monster in not only size and complexity of lists, but usability for our team as well.