I agree with mkc... you really gotta try them out and see for yourself which one suits your needs the best for the way you really want to quilt! It would be a big plus if you could actually use one for a day at a dealer quilting something of your own on your own terms!
This is kinda long, but here is my experience for what its worth...
I have a Nolting Quilting Bee (sitdown longarm). I had visited many quilt shows over a period of years and tried my share of machines available. I wasnt in any hurry - in fact i kept trying to talk myself out of the purchase (need it - or want it?). I have friends who have many, many different brands of machines they all chose for different reasons. I enjoy free motion quilting and only want to quilt for myself. Had i gotten a bigger/more expensive machine i would have felt enormous pressure to make it at least partially pay for itself - i definitely dont want that stress and i know myself well enough at this stage of my life and know that i “just wanna play”!!! 😊
Last year i finally decided that if i wanted one when i retired i better do it now (i am 63). Part of the consideration for me is easy availability to service (Nolting manufacturing is about a half hour away - but they do have dealers all over so, whatever machine you settle on its a good idea to plan on “what if”). Also - i wanted them to bring the machine & set it up - they did! I wanted a machine that was easy to maintain myself - it is. I also wanted a few options (wanted the machine in lilac 😊 and the legs too - also wanted to add needle up/down). My table was included, so whatever machine you decide on find out if the table comes with or is purchased separately.
I dont have a huge sewing room (one of the spare bedrooms left after my sons grew up and moved out to lives of their own). So i measured everything within an inch of its life (over and over and over) to make sure that the machine i decided on would fit comfortably in my room without giving up my ironing station, cutting table, etc - and still have enough room for me and my quilting buddy to move around freely and not feel cramped when we sew all day!
I know it sounds like a lot of stuff to think about when you are so excited you can hardly stand it, but decide whats important for you so you arent disappointed! I am sure there are other things i thought about (in the 5 + years i kept trying to talk myself out of it) but those are the main ones i can think of. I got mine last October (ordered it in August and they built it for me) - no regrets!