Magnepan Active Bi-Amping

I’m wondering if anyone else has tried this, but also if there is a better unit or a better method out there to achieve similar or better improvements in sound quality.

I’ve inserted a dbx Driverack 260 speaker management unit into my system. It provides the means to employ an amp for my Magnepan 3.6R’s low frequency panels, and a separate amp for the mids and tweeters (the internal crossovers between mids and highs are still in use). The dbx has been set up to provide a close approximation - only slightly tweaked - of the Maggie’s manufacturer-listed crossover points and slopes. It does the same job for the Martin Logan Descent i sub that accompanies them. I’ve spent about a week making adjustments and have honed in on what I think is close to the ideal, at least as far as my ear can discern, although no measurements of this configuration have been taken yet. I can list the specific crossover frequencies and slopes if anyone finds it necessary for the purpose of this discussion.

Before I get to the benefits, I’d like to highlight what I believe are the drawbacks. First, inserting this unit into the signal path creates another A-D/D-A conversion. Second, I’m not sure of the quality of the internals of the dbx unit. They may fall well short of the higher standard typically seen in audiophile components. Given the unit’s price ($700) and its typical use, not to mention the added connection points, I find it entirely possible that some signal degradation is happening. But to what degree and to what detriment, I can’t tell from listening. It's possible that I'm still just mesmerized by the speakers' increased liveliness and therefore missing any possible degradation. 

The benefits of this configuration are what I perceive to be a greater authority of the amps over the speakers. The sound seems to be more dynamic, lively and, well, effortless. The Maggie’s 86dB/watt/m efficiency has always been a weak point for me. I believe this configuration goes a long way towards alleviating that drawback. But could it be mitigated with a more powerful amp? The image the speakers present is slightly more pin-point, and maintains that quality across a wider portion of the soundstage. Could this improvement be happening because the stock passive crossovers are being bypassed? Magnepan's crossovers are so often faulted as a weak link, but I have nothing to compare mine to. Has anyone gone to the trouble of having a custom crossover made, and if so, by whom?

I think I've done this a bit "on the cheap," which concerns me a bit. I don't want to be stifling the potential for even better sound quality by using the dbx unit. I would rather spend more money on a better crossover (active or passive) and, if necessary, a more powerful amp (or set of amps) as long as I can be reasonably assured that the results will meet or exceed what I'm getting now in this active crossover/bi-amp configuration. But I feel woefully uninformed as to what equipment to seek out, especially in regards to the potential crossover upgrade.  

It might be worth mentioning that the subwoofer’s integration is so much more precise using the dbx than it ever was with the Descent i’s controls and careful subwoofer placement by themselves. I’ve set what I feel is the best crossover frequency, slope and phase for the sub in its current location. But arguably more important than a flat response in subwoofer integration is the timing. I’m using a delay in the signal going to the mains in order to align the wave from the sub with that of the Magnepans at the crossover frequency. I’ve done all this by ear and with the use of an adjustable sine wave tone generator, so some adjustments might still be necessary after measurements are taken.

So to recap, has anyone seen improvements in their Magnepans by using:
- a speaker management unit or other active crossover and bi-amp configuration, and if so, which one(s), 
- a significantly powerful amp (or pair of amps), and/or
- a custom-made passive crossover network of higher quality than stock? 

(edited for clarity - I hope)