I am basically the opposite; typically a "Chevy Man" but purchased a brand new C in 2019 with the V10 because we knew (or thought at the time) 2019 would be the last year for the V10 (and if COVID hadn't happened it probably would have been.) I wanted the V10 because of its long-term proven reputation in class C, especially with the 6 speed. Also Ford class C outnumbered Chevy by a wide margin. My wife and I each daily-drive Tahoes, we own a 3/4T Chevy pickup, and traded in a Chevy Class C on our Ford; so we are very familiar with Chevy V8 (and still love them.) But zero regrets with the V10 in our C. 20k so far with no issues and if it's half as reliable long-term as people say we will be very happy. That all said, I have zero experience with the Chevy 8.1.
You probably can't go wrong either way, Ford V10 or Chevy. Both are well proven. The newer Ford 7.3 may be great, but I've been on this forum long enough to remember the guys bragging about their new 6.0 and 6.4 Fords.