Last Sat...
I forgot to don my weight belt and had to return to the truck for it.
My buddies re breather computer cables were reversed and I had to tear it apart on his back and re-rout.
My left glove flooded (liner stuck in seal) and we surfaced. My buddies primary wouldn't strike.
The little flashing light thingy of his HUD kept falling out of the clip.
We went down... we came back up... we went down... we came back up. The air temp was about 19 degrees and the water temp was about 42.
"Maybe this is one of those dives we shouldn't make, " he suggested.
"Wanna bag it?"
"Let's give it one more shot."
As we were dropping down the wall which goes from 12' to 130', his backup light dimmed out. I gave him mine.
The rest of the dive was wonderful, except my wet hand started hurting 40 mins into the dive, so I called it then.
As to weight, my betters are already discussing this, but I'll give my 2 cents.
When I dive in S. CA later this month, I'll be diving a gear a different configuration - AL80 with my BP/W, drysuit and less undies (AL 80?? Ugh...). Before I jump off the boat into Catalina waters, I'll make my "best guess" as to weighting. My weight check will be to let a little air out of my BC before we actually descend. From experience, I should be able to tell how close I am without totally descending. I might hand a couple of pounds up to the boat, or ask for a couple. Then at the end of the dive (during the SS), I'll test things a bit and I'll know for sure. No biggie - no one else might even notice while I'm doing a weight check.
Where I dive, it seems like I'm adjusting insulation under my drysuit every couple of months, and from fresh to salt. Weight adjustment is just part of the dive. Unless a diver dives the same exposure protection in the same waters all the time, I would think that everyone would be quickly used to weight checks "on the fly".