I've had real good luck with my rifle builds at UM. I've also learned a lot over the past few years by going into the shop and talking with them. They've always been very helpful and have bent over backwards to help me and other customers I've met in the shop. From what I've seen, it seems they will go above and beyond to make things right and make the person happy. They've shared a lot of load dev data on different bullets/powders etc which has been helpful as well. Build times have been in the ballpark and competitive with other builders myself/friends have used. The quality on mine have been top notch. I hope OP's hammer like mine have.
For builds I've done a 300 prc, bat vesper, XLR chassis, carbon 6 barrel, NF nx8 4-32. Maybe took 6-7 months, I'd guess a lot of that time was waiting on a barrel. Barrels were pretty back logged at the time. It hammers with 215 hybrids and 208 lrht. After a while shooting suppressed with 79 gr H1000 it developed a carbon ring. Not UM fault. Seems to happen with geometry of the case, suppressor use, case trimming, etc. Some 215's wouldn't feed, could see abrasion/scuffing on copper jacket. I tried a lot of carbon removers. Finally went into the UM shop and asked if they had any ideas. Taylor turned me onto Thorroclean. It worked, super easy. Back to hammering. Should of just went in or called them at the start. lol
Tikka 6.5 creed, Blaine tried to talk me into a 6 which he was probably right but I was already tooled up for 6.5 reloading, mcmillan game warden 2.0, benchmark 5, triji tenmile 3-18, scythe ti,140 eldm. Maybe took 3-4 months. It hammers.
7 prc, bat vesper, XLR, 22" ace spiral fluted, NF nx8, 180 eldm. Probably took close to 10 months give or take. A lot of that was probably waiting on backlog of cerakote, they've since added more people to cerakote. It turned out great and it also hammers. Got lucky and drew several elk/mule deer tags this year and it was awesome. Road in truck across half the country several times, fell down a steep mountain strapped to side of pack. Rattled around in my pack on 4 wheeler for hundred miles. Kept zero. Whacked them at 400, 330, 435, 710, 540.