Extra tie-down points, for sure. I like the ones that drop down flush and then lift out when you need to use them. You can always find places to strap down to if you really have to, but having three or four dedicated loops on either side of the trailer makes things a lot simpler.
Definitely brakes on both axles. No question. I don't think anybody ever complained about having too much stopping power, especially when towing a 7000 lb tractor on a 2000 lb trailer.
Some of the break-away emergency brake systems charge the battery off of the 12-volt line when the vehicle is running. Others don't, and you have to take the battery out of the box and put it on a charger. My current one is the latter, and I wish it was the former. I'd love to know that every time I took my trailer for a ride, I was also topping off that battery. I suppose it could be argued that the dedicated charger does a better job and preserving the battery, but the inconvenience of having to take the darn battery out every time is just silly.
I second what a previous poster said about a mount for the spare AND a lug wrench. I don't like having my spare on the front of the trailer because it sometimes gets in the way on tight turns and it makes it a little more clumsy to hop over the coupler to get to the other side of the trailer. I managed to get a bolt-on mount to work on the back of the side of my trailer, but a welded-on mount would be better. I still have to carry the lug wrench in my truck.
If you're getting a tandem trailer, I cannot recommend this item enough for tire changes and other maintenance. Much easier than jacking.
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