So I got my XP3 yesterday. I love Bigalsonline, but it takes ~1.5-2 weeks to get my orders. That's a tough wait.
I was a bit surprised by the XP3. The build quality is excellent. It's got everything I really need in a filter, but but but it's huge. The water level in my tank went down 3" when I got the siphon started (no kidding). When I turned it on a few of the otto's got pealed right off the glass they were sucking on. This sucker is powerful. I can't imagine using the "jet" return... at least in a FW tank. Luckily they have a valve that allows you to slow it down a bit.
It's a bit noisy. I can't hear it a room away, but I can hear it when I stand in front of the tank. It's not loud, but it's not silent. If I had to guess i'd say it's about 30-35dB. It's not an unpleasant sound so it won't be a problem.
It's got all the features and accessories a person could want for a $100 filter. Unfortunately for my wife it's just too darn big for a 45g tank.