To give some input, yes I did pick this trailer up many months ago and have towed with it about 20x.
I can say the trailer is built right, everything on it is sturdy as heck. Possibly overbuilt. The cypress logs are big $$ but are the right tool for the job. Some simple but nice touches that I had never thought of, like using full lug nuts that cover the entire stud and are packed with grease, abound on the trailer. Went to change all the tires on it and found that.
The VIN # is clearly and boldly STAMPED into the top of the frame rail near the tip of the tongue. You don't normally see this, usually it's a metallic sticker that fades after a few seasons. This sounds like a small detail, but think of this: Once that sticker fades, the trailer is open for theft and re-registration by anyone! If the VIN # is clearly stamped in it, it's not as much of a target for theft and can be recovered much easier.
Now here's what I don't like about the trailer: I don't particularly like the bunk mounting setup as I find it hard to adjust. It's incredibly strong, and once adjusted properly you get the feeling it'll never move, but it's not as user-friendly as some of the other trailers I've used. For example, I'd like to have my bow riding a couple inches higher, but the trailer bunk mounting hardware doesn't allow for it easily.
Also, I added a set of PT bunks to help guide the bow onto the front "V" and they work like a dream naturally. Just let them catch the bow and push forward. EZPZ.
I also feel the axles are a touch too far to the rear, at least for my boat. Rolls can be ordered and built for any boat for sure, and mine was originally under a regulator so perhaps the axles were proper for that hull, or the guy just had his transom overhanging the bunks by a bit, which is unfortunately pretty common. I'm sure if you bought new you could spec what you want. Was not an issue till I moved the boat forward 6" to get the transom fully onto the bunks with 1" of the bunks sticking out, and I introduced some sag into the new tow rig. Just installed a 6" adjustable hitch and a set of air lift air bags to offset that, have not towed yet with the bags but tomorrow will be the 1st run, I doubt I'll have any sag now.
But, I'm pretty anal about my trailer setup, and like to tweak it so the boat sits perfectly.
It sounds like the dealer is more the issue with your setup not being correct. A trailer mfg'r can make you whatever you want. Lots of times dealers don't know what a full boat/motor package weighs and they guesstimate low, which is dangerous and it sounds like yours is under-rated. You should not have the scary issues!!!
A 6k lb 23' boat is a lot honestly for that size boat. What brand is it? They have tandem axle trailers that are rated anywhere from 5k to almost 9k lb ratings.
The bunk issue you had should have clearly been resolved pronto. That's not going to last and is in fact dangerous to tow with. That bunk breaks at highway speeds and buddy you're in for a ride when the boat re-settles!
-T