The sound you are getting is a function of the speakers and the room. The guy is full of s*@# and just wants to make more money off of you. By the way, even if you believe all the false claims about some receivers being bright, Onkyo/Integra are generally considered brighter than Denon. Now, again, that's not really true - they're the same. But either way, I do not recommend a receiver swap.
Focal is generally known to make bright speakers, by the way.
Here are your options as I see them:
-Get used to it (probably easier than you think, unless it's REALLY bad... and if it's REALLY bad, then it's probably mostly the room; room-eq can't correct everything, either)
-Try adjusting the positioning/angle-in of the speakers a bit. You generally want them 1/7 or 1/5 the length of the wall away from the corner, or so I have read.
-Try some room treatments
-Get different speakers
If the Audyssey target curve can be adjusted in that receiver then you could try playing with that. Rolling off the top end can 'warm up' the sound. Brightness can often simply mean a very detailed speaker, or it can imply some sort of sibilance or other issue as well. And it's often caused by the room, or at least worsened by the room. I do not know what receivers can and can't adjust the target curve, but I have seen people talk about it in the past.
Edit: Also, as jdsmoothie mentioned below and I previously forgot, do make sure you did the Audyssey setup correctly as well. And you can play with the positioning/angle of the microphone to a degree to try and tweak things. Also, good catch about the 2EQ. 2EQ sucks.
"Vintage" is good for wine, not for A/V equipment.