We stayed there earlier this year. We were in the back row, and extended our stay twice. Ended up spending a week.
My review of Spanish Trails? The staff was friendly and helpful. The laundry was clean and far bigger than typical, for a CG this size. There were two large dumpsters a few steps behind our site, but hardly inconvenient for anyone in the campground, as the place is fairly small. It is located on the main highway going through town, which is exactly where most campgrounds in Moab are located. Couldn't comment about the WiFi. As seasoned travelers, we gave up on relying on CG WiFi a while ago, and use a Verizon Mifi. If I end up at a CG with decent WiFi, that's great, but I don't expect it, since it typically varies from unusable to barely acceptable.
We wrapped up a 16K mile trip last month. We stayed at a few dozen CGs since May, and have been to most of the commercial campgrounds in the Moab area on previous trips. consequently, I wouldn't hesitate to recommend Spanish Trails.