The Image X10i is still the flagship with its use of premium materials & drivers that justify its price...however, there are members here at HQ who do prefer the Image X7i. I can tell you that A LOT of care was put into the Image X7i from both a design and acoustics standpoint. The Image X10i definitely has a little more bass if that's the type of sound you prefer. We are not introducing a new flagship anytime soon. We still love the Image X10i, but we think a lot of people here at Head-Fi may very well prefer the X7i.
I'm not sure. I personally prefer the X5 over the X10 even though I like a punchier IEM. Klipsch comfort cannot be beat though. The best fitting IEM I ever tried was the Klipsch Image S2. They are also the most durable IEM I've ever owned. I work out in these, and have worn repeatedly in industrial worksite conditions and they've never died since 2009. IMHO, the S2 should be made into audiophile grade.
Glad to hear you liked the Image S2 so much and that they lasted you so long...With all of our headphones, you would be quite amused to hear what people have done to them, yet the headphones keep on tickin'.