Razor sharp

I've only been listening to Wu-Tang Clan for less than 3 years, but I've always thought RZA was the best member during the early days. When I listened to later stuff, like his appearances on the solo albums, I was disappointed. His voice no longer had that sharp-like-a-blade quality... it sounded very dull and jaded. His rhymes also developed a very political and philosophical nature, but his delivery was pretty boring. I think his verses on 36 chambers and the gravediggaz 1st album were his prime. Even if I don't like the beats on the later Wu-Tang albums (I prefer the low budget sound), the other members seemed to really develop their skills. RZA, what happened?