Their later works get far more abstract and experimental then the Tri Repetae era, I suggest giving them a few more listens where you really sit and absorb it and see if they grow on you a little more. Autechre is not a group that can be easily absorbed upon the first couple listens (in many cases not even the first 5 listens). There is intricate subtle shifts and changes in the later works that is not always noticable upon first listen, they have also developed an affinity for almost unheard of time signatures. Draft 7.30 took a long time for me to open up to but is now one of my favorite albums by them. Untitled is a bit less abstract but instead makes use of very odd and irregular time signatures that often shift constantly. However thier later works admittedly are definately not for everyone. Perhaps you might enjoy their more minimalistic early works prior to Tri Repetae a lot more? Thier first record Incunabula is a strong debut, and Amber is also a very decent record.

Chiastic Slide is one I haven't gotten yet because I can never find it in any of the shops around me, but I think I may order it soon. From what I've been told it's the middle point in the shift from the early more minimal works to the more complex and abstract and is a great blend of both worlds. I look forward to hearing that one as well.