Yep, that seems pretty good to me, quite stable over 12 miles.
177 is the most I've seen in a 5k and I suspect my max is about 185 having seen 183. It bugs me not knowing for sure and I'm tempted to have a go at the tests that Tommy did a little while back so I can sleep better at night
Muddy - a piss is just about enough warm up for me
McF - for my first I averaged 156bpm which is about 84%, and second was just under that but I had to ease off so as not to poo myself. 88 sounds a bit much to sustain for 26.2 but of course it depends on how reliable your max is ? Was your HR relatively stable ? If so, I'd say that's a good sign, not so good if it's drifting.
Not sure how the post about Skinny got in there as I posted that a while ago ?