I got hired recently to build a loft bed, based on Jay Bates' (he's a woodworker dude with a couple YouTube channels) design, and while the build itself was fairly pedestrian - one of Jay Bates' niches is using a lot of dimensional lumber (off-the-shelf, Home Depot style) - the out of the ordinary projects are always a nice change of pace from the regular stuff. That said, I pretty well maxed out my shop space on this build, so it wasn't the most efficient of operations, and even the installation was a bit of a challenge.
In hindsight, I should have gotten lumber from a legit lumber yard, because everybody and their brother - and certainly myself - knows that big box store lumber isn't the easiest stuff to work with. It only took about 3 hours and trips to 2 separate big box stores to come up with some decent lumber, and it took me about 4 times as long to plane and sand everything to where it wasn't all twisted up and horrible.
Once I started construction everything went smoothly, although I'm not sure that if it had been up to me, I'd have used the same design. Being a structural engineer by education, I have a hard time simply relying on mechanical fasteners alone, like screws, to carry significant loads. Similarly, the design of this bed made it very difficult to keep the bed frame square while doing subsequent work. I don't own any 8'+ clamps, so I had to be a little resourceful and use some ratchet strap tie-downs to hold the frame square during preliminary assembly.
Once all the pieces are cut and assembled, I disassembled everything and stained each piece individually...which took what felt like forever. Then I loaded all the pieces into my ride, drove to the clients' house and got the bed assembled. Assembly only took a few hours, but I was definitely sore the next day from all the wrestling I had to do with a structure comprised of several dozen 2x4s and 2x6s.
Unfortunately...the bed is gigantic, and as it turns out, the clients have a ceiling fan in the bedroom that will probably have to be relocated...or anybody in the bed runs the risk of getting some serious noggin bruises. Regardless, it was a fun project, and with a few design additions on my part the thing is plenty solid...but I'm going to need a bigger shop before I build one of these again.