I liked the faction balancing better in BFME 1 and I hated the walls in BFME II. The idea of picking a site for my base and my walls was excellent, but the implementation wasn't. Walls went down too quickly compared to how much they cost in resources and time to put up. Which is a shame, because the idea of walls really added something for the BFME formula.
All-in-all, I think BFME II had better sub-systems but a less enjoyable high-level game (the customizable heroes and some of their powers were especially kick-ass). BFME is the only RTS I've played that I really enjoyed from moment to moment and I loved doing LAN and Internet games with/against my friends. Something about the way it was balanced and the fundamentals (unit formations, mixed-unit dynamics, etc) really hit the spot. Every RTS I've tried since has fallen short for me, though BFME II and Company of Heroes to a much lesser extent than most.
I came for the LOTR fix and stayed for everything else.