I tried many different machines before I purchased one (Innova). I agree with clements about finding a shop where you could rent time on a machine and see if you really like doing it, since it is a large investment. I am a person who likes doing my quilts from beginning to end.
I started with the LQS near my old house. They bought a LA (Nolting) that they gave a 6 hour class on its use and after completing the class, you could rent time on it. Then they upgraded to a Gammill. I used both machines. I tried both a Tin Lizzie at a dealer and an HQ at a quilt show, but wasn't thrilled with them. The HQ dealer told me that I would have to bring the ~ 45# head into the shop once a year for servicing.
We moved from SFBay area to LV and I tried to find a rental place here. However, the LQS that did rentals was in the process of switching from being a Tin Lizzie dealer/rental to a Gammill dealer/rental and the machines were not available for rental at that time. My husband also said since we now had room for a LA, that I could get one, so I started shopping in earnest. I joined a local guild at that time as well. I mentioned to the then president at the time that I was looking into buying a LA and she recommended that I try an Innova (she didn't own one, but knew about them). I went to the dealer in St George and tried it out and fell in love with it after trying it at their store and also at a local quilt show. The Innova doesn't leak oil like the Gammill and is very easy to move.
However, that being said, you definitely need to try the machines for yourself before purchasing, because everyone is different and likes different machines for different reasons. You definitely have many things to consider with a purchase from feel of the machine to price and space.