My penny's worth: I have a PRS SE Custom 24: I very,very rarely use the 23/24 frets. Wouldn't miss them. The neck pickup is probably the thing I like best about it, very clear and smooth, not boomy or trebley. ((it's also the only guitar I have that I keep the trem arm on- very smooth trem )) I don't notice a hand position change from being 24 fret ( as opposed to an SG , where i DO feel a significant difference- I know what ur saying).
If you're really doubting your choice I would say absolutely order a 22 to compare. I would. Don't worry about Sweetwater's feelings, I would bet this happens often for them. Comparing the two will either validate or alleviate your uncertainty- win/win. U spent a lot of money, u deserve to be totally happy with the end result. Do it now before ur return window closes.
Good Luck/ Take Care