I gave the spec a test run last night, but on Ony instead of Uld like I thought we were headed. In the 10-man, I was paired with a druid and wasn't really able to test it out enough to get a real good feel for it. It did help on the initial pull, though. Shielding the tank just after engaging Ony allowed the tank to get position faster. I had to shield myself and the other healer to catch up with him. Speeding trees make for some good lulz. =)
On the 25-man, I tried to make it work and tank heal with limited success. When the tank called out to bring the groups together, the shield allowed him to snap the two together. BnS helped the stragglers get to the sides during Deep Breath (when I could find them) and allowed my tank (a DK) to reacquire quickly afterwards.
I wasn't able to really put the spec to task though, since the spec does not lend itself to tank healing well and there was another disc in the group that I was trying to mesh with. Needless to say, when focusing on single target heals, the spec leaves a lot to be desired.
We had a few dc's and I lost a tank during P2 =/. In the interest of the group, I went back to a normal disc spec to finish the raid.
I don't count it a failure, merely untested still. I need to have a MT healer to fill my spot before I can really give it a proper workout in a raid healing assignment.