I have had two Equi-Trek trailers and would recommend them. My mare does not like to travel forward-facing, but is fine in the rear-facing Equi-Trek. The L models give the horse more space than a lorry and they are very easy for one person to manage. The ramp is easy to raise and lower and is low and wide for the horses.
It is also very nice to have the dressing room in the front for storage and for getting yourself ready in.
These are heavier trailers than most, so you do need to be a little careful about making sure your twoing vehicle is up to the job.
On the durability side, I did have some problems with my first Equi-Trek, a Show Trekka L. I purchased a 2007 model which had a lower GVW than I thought it did. I would have been very close to overloading it regularly. It did need two replacement axles, although I believe Equi-Trek may have had a bad batch of axles as I am not the only person to have had this problem. Other than that, the problems have been small, the chaine to hold the partition open broke, one of the saddle racks broke, etc. Nothing I wasn't willing to deal with to give my horses a nice ride.
I believe the company has been working on better quality control over the last few years and they treated me well. They replaced my broken axles free of charge, including collecting and delivering my trailer to the yard, and repaced my partition rubber skirt and electrical lead as well.