New Active Crossover... Bryston 10B, JL audio CR1, Pass Labs XVR1 or First Watt B5?

I have the 10B-STD. My system is very transparent and I didn't notice any degradation in sound after installing. If there was any it was far outweighed by the improvements that came from properly crossing over my subs.

Having the flexibility to set cut over frequency, level, and slope independently for each channel is is a nice feature. this helped in my case because one sub is in the corner and the other is not.

I looked into the Pass, but it's over my card limit ;-). The Bryston is too limited in flexibility (slopes, frequencies, etc.). The First Watt B5 is designed specifically for OB loudspeakers and subs, and at any rate is discontinued. So is the B4, which is the x/o you may want (it is VERY flexible: 1st/2nd/3rd/4th-order filters in 25Hz increments from 25Hz to over 6k!). I did, and found myself a used one. It too is, unfortunately, out-of-production. Call Reno Hi-Fi---a major Pass/First Watt retailer: he may know of an available one. 

By "So is the B4", I meant discontinued, not designed for OB's.

Marchand makes various types of crossovers.  He even had some tube ones.  Price was reasonable and he even had some tube ones.

There is a 10-B for sale on usaudiomart right now. Manufactured in 2012 so plenty of warranty left. $1100.