X250.5 compared to Naim Nait5i

Hi guys,

I am new to higher end audio. At present I have a Naim Nait 5i, Cambridge Azur 840 c (CD player) and Dali Ikon 7 speakers. Will running a Pass X 250x along with a Parasound JC2 with these speakers make a big difference to the sound?
I also plan to get a pair of Magnepan 1.6s and I am guessing those with the above equipment would be a big improvement.......what do you think?

I have nothing to compare all this with since my last system cost a total of about $500 - Cambridge Soundworks...(I know) but I am amazed with the sound I have now, however, the high notes on the Ikon 7s tend to be irritating and shrill, almost like having a referee blow his whistle in my ear (is this what you guys mean when you say the highs are a bit "forward"?). I have tried laying carpet in front of the speakers (I have hard floors) and it helps a bit. My dealer told me to hang a piece of tissue over the tweeter but I think there has to be a better fix than that.
Any info regarding the above would be greatly appreciated.
Fantastic site and forum by the way.
Thanks a lot