I generally like the CODA system, but its realization in the LotR book leaves a lot to be desired. You should definately check out some of the stuff at
The Steward & the King as well as the three official documents they put out. (An errata, a FAQ, & something else)
I haven't seen the second printing, though, so I don't know how much better it is.
The biggest complaint (from die-hard fans) is that the formulaic spells are counter to how Tolkien envisioned magic. I, however, am impressed that they made sure every spell reflected something that actually happened in the book.
My biggest complaint was that the one supplement I wanted,
Fell Beasts & Wonderous Magic, disappointed me. I didn't see anything in it that justified the cover price.
In any case, I enjoyed the campaign I ran with it a lot. We intend to restart it in the not too distant future. I may not have stuck too strictly to the RAW, though.
I have also read very good things about free
Legends of Middle Earth game, but I haven't played it myself.
Also, you can pick up MERP books second-hand that can be good additional inspiration.