X2, don't focus too much on the name. I would focus my attention on the dash, as noted above. If you look on the crane (the arm that holds the cylinder when it is "swung out") there may be a number on there (-2, -3, -4... Etc). This indicated which variation it is from the original. So a "no dash" would be the original platform, a -2, would be the second generation (or alteration) from the original and so on.
Generally speaking, people prefer the older models (particularly a "no dash" or a dash 2), and are more likely to pay more for them.