Thought the 026/260 was lighter than the 261?
Is it worth holding out for the pro model?
The "v2" 261 is 10.8 pounds according to Stihl's website. The 026/260 might be a few ounces lighter, but I'm not sure.
Whether a pro saw is "worth it" is pretty subjective to a lot of us. Truth be told there's a lot of good saws out there in the 50cc range that will cut lots of wood and do the jobs you ask of them. I can't honestly tell you that a 260 or 261 is the only saw for you when a 271 or 291, for example, would cut the same wood reasonably well, as would any number of offerings from Husky or Echo, just to name a few. All that said, there's absolutely nothing wrong with wanting the "pro" saw, and going for it.
A "pro" saw will be somewhat easier to work on or rebuild if you ever need to do so, the magnesium case should prove tougher than any of the polymer designs, and pro saws tend to be lighter and commonly are more powerful, too. If you've got a lot of cutting to do, then you'll probably appreciate having the pro saw, but it's not the only an absolute "must."
Personally, I bought pro saws.