I was thinking of putting on some RV bubble levels on the QS. Right now I just use a small construction level and take it around the trailer..
https://www.amazon.com/Camco-25563-AccuLevel/dp/B000EDUTOA/ref=sr_1_5?ie=UTF8&qid=1467312249&sr=8-5&keywords=rv+level
question is: how would you know when you've attached it correctly? I find that different surfaces around the trailer read different level, seemingly due to construction irregularities. I usually take a reading on the frame yolk up on the tongue, on the steps frame, on the back bumper, on the side walls, etc..
I just use my phone on the tongue. Bubble level give you x-y in degrees. I believe our bed is about 1.5 deg out of level so I aim to have the trailer 2 deg or so high on the port side so blood isnt pooling in my head during sleep. I also like about 1.5 deg nose up so i am not rolling into the wall.
Those stick on levels are cheap, so I bought 4 and stuck them all over. That way I have multiple checks on level and can see one from anywhere. I did make sure the places I put them were actually level using a carpenter level.
Level the trailer with the level you are currently using and then apply them in the level position regardless of construction edges etc.
I use the trusty little bullet level. I've used the little stick on bubble levels on other trailers and they have done the job as well.
I added this little guy, works great for me.
(http://uploads.tapatalk-cdn.com/20160701/bf7c22c66899c960559eeb531812de26.jpg)
[a href="https://flic.kr/p/bBY1xc"]
(https://c2.staticflickr.com/8/7047/6970573121_65539711b3.jpg), on Flickr