I just completed a Del-Ton 16" Middy rifle that was built from a kit. So far, I only have about 80 rounds through it, but they have all fed, fired, and ejected without even a hint of problems. I fired a mixed bag of XM193, PMC Bronze, Ultramax, Hornady steel, and PPU 68 gr OTM to function check and zero in my scope.
I dealt with Pam at Del-Ton, and she was a pleasure to do business with. She was quick to answer questions and was very helpful. I was originally quoted 4-6 weeks for completion, but I had the rifle kit at my doorstep 15 days after ordering it. I originally ordered the rifle with a YHM low profile gas block that is a $20 option. They were sold out of them, and it was holding up the build of my upper. Pam contacted me and said they had a PRI low profile gas block, and they would build the upper and ship it the following day if they had my approval. Long story short, the PRI gas block sells for around $50 which is $30 more than the YHM block. I inquired about the extra cost, and Pam told me not to worry about it. I had an email the following morning with a UPS tracking number and had the rilfe 2 days later.
During the build phase of my stripped lower, I ran into a snag when I found the pins supplied for the FCG would not fit the RRA 2 stage trigger that I ordered. One call to Del-Ton and I had the correct pins on the way, along with a pre-paid envelope to return the incorrect pins. In this day and age, it's nice to deal with a company that cares, and doesn't make excuses.
I know it's early in the life of my Del-Ton build, but I can honestly say they're a great company to deal with. They might not be considered a Tier 1 company, but they've earned my business.