I have one installed on my Fleetwood - (re-branded Adria Adora). As its a European van it has a longer draw bar than most UK vans meaning there is plenty of room and no interference when turning (Ball to locker door is 1350mm). Previous to this I carried the bikes inside the caravan, and toyed will lots of options before the rack i have came up on TM at a "what have I got to loose" price. Now I am looking at how to transport 4 bikes - I expect roof racks are the only option. A rear rack on the van would mean 60kg of bikes and carriers - eating into my 250kg payload and weight distributed where it far from ideal.
Installation is easy enough - I had to drill though the plastic draw bar cover and then extend the metal brackets as the fittings the rack comes with wee not wide enough with the draw bar cover (Newer models might have solved this)
The main drawback I have is access to the front locker is impossible with the bikes on, and difficult with the bikes removed. Even if you remove the support, the two rails make lifting a gas bottle in or such like in a little more difficult. There is a model that tilts forward to help solve this problem though, and could be worth investigation. The model displayed needs a bit more forward planning when packing - things you need like power leads and leveling blocks I used to carry in the front locker I now carry in the tug. The main issue is when I forget to turn the gas off before loading the bikes. Another drawback is the bikes pickup road grime and dirt - especially if raining. I don;t worry about a cover, but if you have $5K machines you may want them elsewhere or to cover them.
One advantage is I can see the bikes though the rear window - something I like.
The Alko hitch is rated for 100kg ball load, so with the bikes on the rack (about 30kg) I tend to target the upper end and go for about 95kg when loading - Tug can handle the weight anyway.
Overall, despite the drawbacks, I highly recommend this rack, especially on a single axle. If I had a tandem axle, I would probably go for a rear rack.
Don't be alarmed when you see me talking to myself, I am getting expert advice.