I have to agree with your point about needing to go through the whole program, both levels. Some languages also have a level 3!
The early units are just building a foundation. The later units add a lot of vocabulary and useful situations - but you have to get there first.
Good comparison to Pimsleur as well. It seems that even when people like Rosetta Stone over Pimsleur, they offer a fair review of Pimsleur and aren't too negative. I think that's testament to the excellence of the Pimsleur method, but also testament to the power of Rosetta Stone when you use it right as you did.
I think it's a matter of learning styles. Try the demo for Rosetta Stone and a sample of Pimsleur to compare, and work with the one that suits you best!
