Short answer is that it depends on the 30cc saw. A lot of the saws in the 30-45cc range weigh 9.5-10.5 lb which is about what an 026/261 weighs. If the saw is going to weigh over 9 lbs, then I want a 261 because its a very powerful 50cc saw and I can't tell the difference between carrying around a 9.5 35cc saw all day and a 10.8 lb 50cc saw. I'd actually say the 9.5 lb 35cc saw wears me out quite a bit more because it cuts firewood noticeably slower.
For purely a limbing saw, I've looked at the Echo 2511P several times. The only reason I haven't bought one is because they don't yet have a good presence on the used market meaning I'm too cheap to pay for one. For anything up to 4", I think it would be a very good choice. I don't cut any firewood smaller than 6", and most of it is in the 12"-20" range, so I mostly use my 026 for limbing and my 036 for bucking.
A short story that opened my eye's to the value of a small, light saw. I've only run one saw that was less than 9 lbs (Echo 350 I think). It belonged to a friend of mine and we were doing some disaster relief work down in TN. He's in his 70s and had tweaked his back slightly a few days before, so he stayed off the saws. When we asked ahead of time I was told there were some bigger trees to deal with so I took an 036 and my 066 clone, but left my 026 at home. When we got there, we ended up working a different area that had mostly small cedars, and most of it was under 6". After the first few trips up and down the hills with my 036, it was time to refuel and my friend told me to take his little saw up and run it to get some hours on it. I think it weighed around 6 lb and was PERFECT for what we were doing. Cutting a 12" log required a little bit of patience, but it zipped right through the little stuff (>4") which was 90% of the work. I ran that saw the rest of the day and left both of mine at the bottom of the hill in the truck.
