Brushandthimble is right - you will get a different answer from every one who has a long arm! I've had my Gammill for almost 8 yrs & the only thing I would ever replace it with is a newer one! It has the stitch regulator, (which I LOVE) but not the Statler Stitcher, (which I don't like). G' are expensive, but IMO worth every cent. They're amazingly reliable & the little bit of service mine has needed in 8 yrs has been minimal & easy to obtain. (Actually, the service tech comes to me which is great!!)
Your best bet is to try as many as possible, look at your budget & how you intend to use it. Also important, the amount of space you have available to put it!! Quite an issue with most long arms!! Good luck! & have fun shopping!!