It's very hard to say that one marker is 'better' than the other. It really depends what features you are looking for. Personally, the Legend has never appealed to me at all, so for me, the Quest is obviously preferable, despite being $50 more.
It's a great price for a new '07 Quest anyway, even better considering what the cost of the Critical upgrade parts would be if you bought them separately.
Of course, none of that means anything if you don't like spool valves in general, or the Quest in particular.
I own both and you really can't loose. They are both reliable.
I like the fact, that with the legend, the only maintenance required is oiling the ram every 10,000 shots and the reg once a year. Perfect backup or loaner.