I have the 23.5 powering my upper panels on my Martin Logan Monolith IIIP's and a ML3 powering my woofers and I use a Ref 3 as my pre-amp. I find the Ref 3 works wonderfully with my setup. I have not heard the ML 32, but knowing the Mark Levinson quality, it is probably on par with the Ref 3. Take both home and listen to make an informed evaluation and purchase. Most stores will allow you to take units home for evaluation if you give them a credit card. do not change anything else. Don't play with cables or other components. Do a directly comparison and hear the differences.
enjoy.
enjoy.