I used the AX-7e with an Ayre Codex DAC to drive a pair of Harbeth SHL5+ for many years, When the EX-8 came out my dealer loaned it to me for 3 weeks. The EX-8 with built-in DAC was a dramatic improvement over ther AX-7e. I compared the amp and DAC separately and each was better than the AX7e/Codex, individually and together. The DAC in the EX8 is much better than the Codex which is really good to begin with.
Eventually I went with the Aesthetix Mimas but the EX-8 was a very close second. The AX-7e is still a great sounding amp for a lot less money than the other 2 but if you are looking for better sound and the budget works for you the EZX-8 is a winner