Might I gently suggest looking at a somewhat larger saw? I recently went through a similar debate to the one you're facing. I need a saw for occasional use, and I pretty much need it to do everything because I wasn't planning to buy more than one saw, while looking for the long-term.
A long term solution, to me, meant the ability to handle somewhat larger wood, if necessary. With that in mind, it seems that it's tough to depend on only one saw if it's much less than, say, a 50cc saw. Others may prove me wrong, but, as a casual observer, it seems to me that 50cc is one of the more versatile engine classes. I think you'll find that most 50-55cc saws can be fitted with a 20" bar and chain, albeit they may underperform in hardwood, they will get through it, and you won't break the bank to acquire the saw. At least around here, 20" will get through most everything that would need cutting, and it's nice to have the ability to go to that size when needed, while the majority of the remaining work can be done with a 16"-18" setup. I think you'll also find that most 50-55cc or so saws aren't especially heavy, so it's possible to do smaller work and limbing with them, especially once fitted with the appropriate length bar and chain.
So, if you're willing to handle a little more weight in exchange for a little more capacity, I think you may be happier in the long run if this saw is to be the only saw you plan to own.