In general, the only answer to this requires the questions of Moemoney to be answered. I currently own the BAT VK 60 amplifiers in mono configuration, 120 watts per channel. I also own a Mark Levinson 331.5 which I believe is going to be fairly similar to the 383.
With Wilson speakers, the difference between the two amps types are noticeably different, but both very, very good. The BATs do a great job with the Wilsons, especially in mono configuration. The ML also does a great job, some of the typical differences you would expect.
With my Thiel speakers, the story is a bit different. The Thiel speakers are much more of a power consuming speaker. The Mark Levinson drives them great; however, even at 120 WPC (more than the Levinson is rated at), I don't think the BATs do as good of a job. I find this especially true when playing at lower to moderate volume levels, which was a bit of a surprise. The ML definately had better lower frequency control.
With the Wilson's I actually like the BAT's slightly better, but really love both these amps with these speakers. So again, the matter will be determined based on your other equipment and what the objectives are.
Both BAT and ML make great amps in my opinion. The VK 60 amps are great with many speakers, but I think more efficient speakers than my Thiels are required to really get the full benefit of the BATs.