Has 910's New Firmware helped or made things worse?

The latest firmware update has definitely helped mine.

My pool swims are much more accurate now for distance; however, current pace is sometimes on, sometimes blank. The pace issue happens on OWS as well. It used to work just fine. I have a theory that if I push lap it will then display, but I think it may be lap pace and not overall. Haven't tried this theory yet, though.

Run instant pace is pretty good now, for me anyway.

A problem is that the ant agent is not automatically sending to Garmin Connect. It does send to the Training Center, but not to GC. I've checked the settings and it should be working correctly.

I do sometimes wonder if their QA process includes regression testing. 

My race pace is better than before.  It is still spotty at times.  Before firmware -2-3 min/m swings, now maybe 30 secs - 1min.  I go off of effort now and just reference the garmin.

You know, they will let you keep your watch while sending the replacement as long as you will provide them with a credit card number.  If the broken one isn't back within a certain amount of time they'll charge your card.  But at least you're not without a watch for a week.

Now, granted, in your case the watch wasn't functioning.  But if you have a semi functional watch and don't want to be without it for the 2-ish weeks it takes to get it swapped out then there in another option.  But you have to specifically ask!