I've had the Logitech version of the X-56 for a few months, now, I really like it. I've owned pretty much every HOTAS available for under $400. (Cnd)
Personally I found the ThrustmasterT1600M HOTAS to light, especially the slide Throttle. I debated adding weight to the bottom, because besides that, it is very good setup for the money. The hall sensors are very accurate and smooth on the stick.
I liked CH because of the trim wheels.
The X52, I did not like the stick Resistance. (there was not enough) The X-52 pro was better in that way, but I did not like that the Throttle had to connect to the stick via PS/2 conection. I found the connection flimsy.
I prefer both devices to have independent USB connections.

Keep in mind, these are just my opinions. But The Logitech x56 (gray) is my favorite device.
I did have to calibrate the twist rudder (had to search internet to find solution). But it has been find ever since. The throttle Resistance is very stiff at first, but improves over time.
Plus I hear Logitech are really standing behind this product's 2 year warranty. Going as far as asking customers to show a video of them cutting the wires of the devices, instead of returning the product via mail.