I'll be honest - I'm actually glad I didn't build mine myself.
Couple reasons for that.
First, I just wasn't excited about the overall quality of a bolt-together trailer like the HF models. Nope. Just not at all.
Second was with the build itself. I would have had to buy a decent amount of tools and learn a good bit along the way. I'd have made mistakes, and had basic quality stuff I wouldn't have been happy with on the first run. I've built a good bit of stuff myself and I know how that stuff works.
I feel like I got a much nicer final product out of the deal by having it built for me. The trailer is absolutely better (all welded and powder coated, IIRC, by a place in Iowa). Wheels and tires are absolutely better than what I'd get on a HF trailer. I've got electric brakes with a brakeaway safety setup. I would have been really doing a lot of learning when it came to the electrical system. So not having to figure out and wire all that stuff up saved me lots of hassle. The body of the trailer itself is clad in aluminum and diamond plate, which is definitely not something I'm equipped to mess with.
I was more or less stuck with the body plan of the builder I chose, so that can be seen as a negative (no bike garage, for example). But on the flip side of that, I feel like this particular body plan offers a lot of capability for customization, particularly with the galley. I've got some plans to tweak the organization in there to make it easier to get my kitchen set up and operational once I hit camp. One biggie I want to set up is a cooler slideout. I will probably also add some sort of modular drawers on the middle shelf, too. And I'll probably try some stuff that I don't like and I'll change it. I'm also working out in my head a sort of meal prep station. Something with bins I can use for dishwashing, but can cover up with cutting boards. It will be some sort of exterior shelf or standalone table that I can fold up and stow in the galley for transport.
I'll also probably be adding a propane tank holder in front of the tool box that'll fit one of those 20lb cylinders (I have two that I'm not using at the moment). Then I could run an extension hose from it to my camp stove, and maybe even one of those splitter trees I can put a lantern on. One of those 20lb tanks would last forever and would avoid the trash of those green 1lb cylinders (that's what I used on this trip 'cause I had a few laying around).
With better organization, that'll mean less time in setup/takedown, and more time relaxing or riding. Where the bikes go will probably depend on the vehicle I use to tow it. I'm considering putting a hitch on my Honda Fit so I can use the trailer for solo trips close to home. I wouldn't drive more than an hour or two pulling it with the Fit, but I think it can handle that much.
tigris, you might consider these guys. http://www.tcteardrops.com/
It sounds like they're based up your direction. I was considering them for my build, but I found a builder even more local to me, and TC Teardrops sounds like they've got a longer wait time than the builder I used (TC has ONE shop whereas Hiker has TWO).
I am extremely happy with how my Hiker tows. Yeah, it may make the Subie eat gas, but it's barely noticeable on flats or even on most downhills, which is something I really can't say about every other trailer I've pulled in my life. Some have handled like pure crap. I attribute the majority of that to the well build base of the trailer itself. It's got good balance. I think the wheels being outboard of the trailer body helps quite a lot with lateral stability. I don't have crappy skinny wimpy trailer wheels/tires.
I have a friend who has built a few trailers. He had a homemade teardrop a couple years ago. He's got one now he calls the "Gypsy Wagon" that's a standee and he's just finishing up a whole suspension overhaul on it. Moving the axle back to put a little more weight on the tongue. Beefier axle/suspension. New, wider axle to put the tires outboard of the trailer body (he almost doubled the axle width). Wider wheels/tires for more contact with the ground. The last time he pulled it, he had a pretty terrifying experience with it, so it needed work. That's all stuff I just don't want to have to deal with. Particularly the terrifying towing experience if you get something wrong.