I'm 5'11 and felt my Sentinel (large) was on the small side. The Spire however is a more modern and feels like a good size large, and thus feels great fit wise. The steep seat tube keeps the top tube shorter. If you use it for a bit of everything it might feel big but if you're using it mostly for dh use you might find it just right if you like longer bikes. I also like to look at the front center measures when making those decisions because that helps tell how the bike feels while standing in terms of your relationship to the front wheel.
The new Patrol fits much smaller than the Spire, imo, even though they look similar on paper. I had it before a Sentinel and now Spire. I'm sure it will work for you. When all is said and done it is about what you feel comfortable on and how you like your bike set up. The short top tubes of modern bikes gives more flexibility to upsize. I think you'll be surprised at how the Spire doesn't ride like its numbers. Due to forest closures lately I've ridden my Spire on easier trails and have been amazed that a 170mm bike can still be fun in such situations.
didnt you go from a sentinel to a spire seem to remember?Carbon Spire has internal cable routing tubes, no rattle.
I have seen a few accounts of the BB shells de-bonding, don't recall if it was Spire in articular but they are all share the same construction. But seems to be a very small issue numbers wise.
For a loss of about 3lbs, it's a good upgrade!
Transition had small huckleberry carbon frames in stock for the past few weeks (gone now), if they were mediums I would have jumped on it.
