Seems like everyone here has the same general opinion. XD
I honestly agree with most of what's been already. Reading this for years, waiting for it to build up to some grand finale, then the ending just kind of jumps up on me. No explanation to Negi's love interest, Nagi's rescue not even being shown, when it was talked about so much before hand, it all just felt rushed. The redeeming fact about it is that it showed how most of the characters' lives turned out.
Overall, enjoyed the manga as a whole, had some weak points here and there, but this ending was just disappointing. Hopefully Bleach can manage something better.