I noticed a slight delay as well.. but sliding out the keyboard is instantaneous.. so thats how I boot mine up.
Smart Phones I owned in Chronological order..
HTC Universal (upgraded to WM6)
HTC Dash (upgraded to WM6)
HTC Dash 3G (My FAVORITE Phone)
HTC Tilt2 (AT&T Unlocked on Tmo - speaker went out)
HTC HD7 (Phone too big & no keyboard - and too delicate)
DELL DVP ( OS 7.8, FW 7720.219 )
Someone tell HTC we want a phone like the DVP, if they make it I will buy. I NEED a Portrait QWERTY WP8 device.
That or the 2010 HTC Trophy "protoype" (See Avatar)