This is a super image Paul, a lovely tranquil scene
I like Mark's composition. I'd like the actual processing (exposure, contrast, sharpening, colour etc.) to be somewhere midway between Mark's + Matt's: Mark's tree is nice + sharp with lots of detail, but still needs to stand out from the BG a bit more to make enough impact to keep my attention for longer than a nanosecond; but I think Matt's is just a tad OTT + made the tree too dark + as such it has lost some of the sharp detail + finer tones, especially in the reflection.
Having said all that, I think they're all good