Luxman 505UX vs. Luxman 550AX Integrated Amps

Has anyone compared both of these integrateds? I own the 505UX and like it a lot but am looking for more solid state slam & punch. I actually borrowed the 550AX Class A amp for 1 month about a year before I purchased the 505UX. The only thing I remember about the 550AX was that it sounded much more powerful than it's power rating suggested due to it's high current.
I realize the Luxman's are very refined and have finesse but my 505UX does rock out so basically what I'd like to know is if the Luxman 550AX is more ballsy than the 505UX.

Ok, cool, and sorry about that.
Well I've had my L550ax for about 2.5 years. I too wanted to simplify, I had a CJ Premier 140 Tube amp and and EAR 868 Tube Pre. Can't say the Luxman is better but I can say I haven't missed the tube stuff. Lux is easier to live with, does a great job with my Sonus Faber Electa Amator II's and the MC pre works well too. Sonus in my main system but my other system is Magnepan 1.7 based and the Lux works fine with them as well. Can't turn the thing past 12 o'clock in either room. For reference my other integrated is a NAD C375Bee. Damn nice as well. I've been an audiophile kinda guy for a long time but (almost) off the gear bandwagon (sort of). Except for the new Chord Qute EX DAC with the Lux. Of course. Well that's another thread. If you're in the NYC are glad to demo over a weekend.
Very good info. Thanks!
My first audition was the Luxman 550ax and I thought it was terrific. The next step, of course, was to listen to the Luxman 590ax. It was a huge improvement over the 550ax and was more expensive. After listening to both units several times, I decided to replace my Ayre AX-7e integrated amplifier with the Luxman L-590ax class A amplifier. In addition, I wanted a fully balanced integrated amplifier like the 590ax.

I was "surprised and shocked" at how much better the Luxman was over the Ayre. Of course, there is a huge price different but I felt the extra dollars were justified because of the improved sound.

In summary, the music is fuller, with more detail and with better bass control. I am hearing more things than I did with the Ayre AX-7e amplifier. The mid range is outstanding. I do not understand but classical music sounds better on the Luxman than the Ayre. The music is clearer, more airy and easier to listen to. Overall, the new amplifier sounds excellent in my system. I listen to classical, jazz, blues, country and new age.

I recommend you give the Luxman 590ax a listen. It drives my Sonus Faber speakers perfectly and class A sound is excellent.
Comparison to the similarly-priced Ayre AX-5 would have been interesting.