There are numerous on-line reviews of Vertical Oscillating Spindle Sanders that lists the pros and cons of various models. You should check them out.
It depends on whether you want a ?Light Duty? general purpose, Bench-top model or a ?Heavy Duty? Floor Model that will handle any sanding chore you may have. I use both types almost every day and would recommend getting a floor model, if it?s within your price range and have the space for it.
I see both Delta BOSS and the Ridgid Combo sanders are mentioned above. I have both and use them almost every day. They each have their pros and cons. They are both good for light duty sanding, but have the limitation of only having 4-1/4 " long spindles, compared to my floor model, Enlon, that has up to 9". The BOSS has a much better table surface than the RIDGID, but the smallest sanding sleeve is 3/4" dia. where the Ridgid and my floor model comes with 1/2" dia. sleeves, which comes in handy for smaller arcs. The BOSS has a 7/8" vertical travel and the Ridgid has only 3/4". My floor model has a 1-1/2" vertical travel. The Bench-top models have five different dia. sleeves: Ridgid 1/2" to 2", the BOSS 3/4" to 3". The Enlon has nine sizes from 1/2" to 4".
I probably do 80% of my sanding on the Enlon, I can chew off wood much faster and not worry about burning hard woods because of the greater vertical travel of the spindle.
If I were to replace my Enlon, which is no longer being offered in my area, I'd probably purchase the "JET" floor model. From the reviews I've read it rates the highest.