Hgeifman, if you found the Luxman 550 to be a great match with your speakers and CDP, no need to second guess yourself. Unless one has hard to drive speakers, 20 watts is more than enough. Furthermore, the Luxman integrated amps are excellent amps.
Here are some thoughts from a review of the 590ax from audiorom:
The market price of the L-590AX extends to 8,500. I do not think it is too much as a future owner will get a state of the art integrated amplifier with no reason to change it in next few years. He or she will have no choice anyway as there are no serious contenders. Adding extra 2,000 will buy you the Accuphase E-560, however, apart from its slightly deeper bottom end, you will not get much more. I should also add that the L-590AX includes a very good MM/MC phono preamplifier so one can save substantial money having such a all-in-one solution. If you still want to boost your listening experience you would have to invest into separate Class-A components (a preamplifier and a power amp) indeed, it is a way, but not in this price segment.
Here are some thoughts from a review of the 590ax from audiorom:
The market price of the L-590AX extends to 8,500. I do not think it is too much as a future owner will get a state of the art integrated amplifier with no reason to change it in next few years. He or she will have no choice anyway as there are no serious contenders. Adding extra 2,000 will buy you the Accuphase E-560, however, apart from its slightly deeper bottom end, you will not get much more. I should also add that the L-590AX includes a very good MM/MC phono preamplifier so one can save substantial money having such a all-in-one solution. If you still want to boost your listening experience you would have to invest into separate Class-A components (a preamplifier and a power amp) indeed, it is a way, but not in this price segment.