The one thing it doesn't have is balanced inputs and outputs. I like how my sims (pre & power amps) sound in balanced mode.I would enjoin you to consider a second subwoof instead of an external electronic xover. Sonically, there will be little if any perceptible difference between balanced & SE at low frequencies. There will be perceptible & significant difference b/ween one & 2 subwoofs.
Anyway, amongst the units you list, the Marchand is the usual culprit, well made, good sound, & dependable.