Wow, if only I knew... Judging by volume of main compartment of 3000 cu in, accordingly to Ray Jardine recommendations, 65L is close enough to be optimal year-round for any AT/PCT/etc through-hiker and with aluminum stay it is even more capable of carrying weight than his frameless pack.
But I'd stick with mine. First, because I measured mine and all the gear I usually want to take with me on a weekend trip fits into it comfortably. I did winter backpacking even with a smaller pack, and I should be just fine. Extra volume invites extra weight.
Second, because I cannot exchange it anyway
And in the long run, I plan to pack lighter and smaller, not heavier and bulkier.
Yet, for anyone who is thinking about buying one, either would be a great pack, but bigger might be better. Or not? Depending on how you think about it.