I have pulled the Newline trailer since 2005 and still think it is the best way to go. There are occasions when it feels like there is more effort to get the whole rig upright but not always.
When we went to the GTG at Cripple Creek, there was another "05" owner with a red Newline that he had put a two-legged kickstand on. It was chromed and looked good and worked good. It was his own design. When the legs were up, it was almost invisible. I just have a three legged stand that collapses flat and I carry in the trailer when I'm on the road.
Yeah, It's a little tippy feeling when it's not attached to the bike. You have to stay low with it and I always have the stand ready to slide under the frame. I don't know if it helps or not but I carry a short length of chain and a padlock to secure it to the stand and something unmoveable nearby.
Backing it into the garage is no harder than backing any trailer.
I don't know what you mean about the "free water" effect but it is really not noticeable when you are pulling it. I like the fact that it tracks in the same track as the bike. When you hit a bump, there is no side to side effect that is common with two wheelers.
My biggest complaint about the Newline is way it attaches. It does not have a ball, it slides in the receiver and is bolted on. Therefore, you have to carry wrenches and lay down to bolt and unbolt it. It also has a set bolt that must be dealt with. No big deal, just something else to lay on the ground for. My buddy has a two wheel rig and his is on and off in a flash while I'm getting down to start wrenching.
You can see pictures of mine in the old gallery section on page two.