I use the BAL for the PUP now and I have to say, probably in the minority,  but I'm not a huge fan, to much work. If I had it to do over I'd invest in the Lynx levelers.

I used to use wood to level and have seen the lynx leveler.  I think the lynx leveler is the same as wood and wouldn't pay for that.  I now have a BAL and it really truly is easy to use IMHO. 

I don't believe 2 BAL's will fit under a dual axle.  I don't see why they can't make one that is in the shape of an E for a dual axle vs a U for a single axle.  Until they design something like that you will have to use boards or lynx levelers.

My Dad uses something similar to these
http://www.blaylockind.com/ezjack.asp

I've been using Lynx levelers.  After doing it about 10 times or so now, I can usually nail level within 2 attempts. 

I thought about going the double-BAL route, and decided against it, since they're pretty heavy and bulky, and I can't leave my trailer leveled for long periods of time without having to worry about rust.

If your tires are reasonably close together, using the wheel-lock type chocks really simplifies things (http://www.rvwholesalers.com/c.....-0277.html or http://www.rvwholesalers.com/c.....-0266.html), especially when you're up on blocks and can't easily work a normal chock in there.  It also seems to me to make the trailer much more stable since the two wheels are locked together.