Bear in mind that the chainsaw is one of the most dangerous machines man has invented, and all saws will kick back and bury themselves in your head if handled badly. As long as you have a good instructor the CS30 and 31 courses will make you a safe user. Don't fear chainsaws for their inherent ability to kill you, but respect them.
I used to have a 346 and they are cracking saws, but the best you could do is go to a good dealer who will let you pick up and perhaps even try cutting both the 346 and the ms260. One of them may 'fit' you better than the other. I don't see the point of heated handles when you should be wearing approved chainsaw gloves. Heated handles might be good in Canada in the winter but in the UK with spring and summer approaching while wearing gloves anyway? I think not.
When choosing saws I am guided by their power to weight ratios. I am not the biggest bloke so I like lighter saws as I get less tired using them. My current machine, soon to be replaced, is the Husky 262xp. With 4.8hp available out of just 11.6lbs (powerhead) it has a power to weight ratio which has never been bettered, yet it is nimble, agile, reliable, has great anti-vib, and a good one will run bars from 15 to 24 inches.
I'll write it again - all saws are inherently dangerous especially in untrained hands, but in my view semi pro or low power chainsaws are more dangerous than the others. Work all day with a gutless saw and you will get fatigued, and a tired chainsaw operator is a nasty accident waiting to happen. Conversely, given that power = the capacity to do work, the more power a saw has the less work you have to do. If you are less tired, there is less danger of something bad happening. Therefore it follows that feeble saws are more dangerous than powerful ones.
So if you are a hulk and can comfortably work with a ported 385xp with about 8hp on tap, get one. It will do so much work for you, life will be a breeze.
My advice is don't be swayed by those here who have their feet firmly planted in either the Husky or the Stihl camp (or Makita, Tanaka, Solo, Jonsered, Echo et al); try first then buy the most powerful chainsaw (i.e. the saw capable of doing the most work) that 'fits' you, and which is light enough for you to comfortably use all day while wearing all the mandatory PPE (including gloves!).
CS