Great TR.
As for the descent, while it does tend to seem longer than it actually is, I personally kind-of enjoy the rush of the quick descent down to the Portal from Trail Crest (for me, the part that is hardest is always the half-mile ascent from the JMT junction back UP to Trail Crest on the return trip -- that just kills me every time). But once I'm back up to Trail Crest on the return trip, I take my foot off the brake, put it in auto-pilot, sort-of throw myself down the hill, and just cruise down the entire trail at a near-jog/run, unless I have to stop and help someone.
Sorry about the naysayers at the trailhead. Except in a painfully obvious circumstance, no one has any business telling you they think you won't make it to the summit, especially if they don't even know you or your capabilities. I'm guessing whoever it was who told you this
may have made that assumption based more on their presumption that you were first-timers, which of course, doesn't matter. But who knows... You
did made it, and that's great! But it would have been a great experience even if you had not made the summit. So, you proved them wrong!

CaT