What concerns you about that? Mountain waves?
That too - forecast says max VSP 800fpm - but flying for hours in IMC being constantly thrown about is incredibly tiring, even with an autopilot.
Why non-standard? I haven't flown it, but the SID looks like TLA at 6000
Indeed, but unless you were lucky and hit a period when there was no-one else wanting to fly the TLA SID they'd be unlikely to accept someone climbing slowly at, what - 90 knots? - and clogging up the system. In still air you might struggle to meet the 7.4% procedure design gradient too, although I accept that on a day like today with a southwesterly hoolie you'd probably be going almost straight up so that wouldn't be an issue.
NS