Get Backers manga indeed has 26 episodes thus far, and shows no sign of ending anytime soon. I don't know about TokyoPop's translation (since I collect the Chinese Tong Li version), but the manga is great! Very funny and a lot of action. The 2nd Infinite Castle arc in the anime did not appear in the manga, so basically I think the anime & manga have been cohesive up to volume 12 or 13, around the arc where Gengi & Ban were asked to steal the arms of a statue; after that it's all different. Shido's back story was taken care of in the past 5 to 6 volumes with some awesome fighting from Dr. Jackal~~ and volume 26 was some history telling about when Genji & Ban first worked together and how they met Heven & Natsumi.. it will be a long way before the series end.