My wife and I did the trip 2 years ago, and it was great. Bosque is very nice, but the abundance or lack of birds will depend on the weather. A hard freeze will send many birds away. For variety, the area around the visitors center is good.
For the snow geese and cranes, the best spots are actually outside of Bosque, the ponds about 5km north of the visitors center is the best spot in the morning to see the cranes extremely close, and if they aren't frozen, lots of waterfowl too.
For late in the day, check out the Bernado wildlife refuge north of Socorro. We had many times more geese up there than Bosque itself, and the constant stream of birds is quite the sight.
I can't remember the name right now, but there are some canyons south west of Socorro about 30min's away and we had Cactus wrens, Oak titmouse in that area. Further south along the hwy is Elephant Butte when we had very close Western Grebes.