Posted my first impressions in another thread but it is more on topic here. Mine arrived mid-day Friday. I ordered the green Alpine band, which I'm having serious reservations about...but here goes.
Stunning looks. I love titanium, and no one does industrial design as well as Apple.
The crown guards make a lot of sense for an "ultra" watch that may get rough use, but they do make crown access tougher. With gloves it might be almost impossible (haven't tested that).
The display panel looks really good, better than my S7. The resolution seems higher and the colors more vibrant. Maybe the panel is better, or maybe it's an illusion caused by the flat crystal, or...?
I really like the Wayfarer face but it can be crowded if you use all the complications. I removed three of them. I also really like being able to switch it to a the dim red version with a twist of the crown.
Battery life looks to be longer than advertised. I've never had a problem with the earlier watches, going back to Series 3, but this is a whole new game here.
Some negatives, too, though.
The 49mm size is not a problem in terms of its two-dimensional size, but the third dimension is surprising. This watch is really tall. Possibly enough to be really inconvenient...I have two weeks to decide.
The Alpine strap is (personal opinion warning) a nutty design that's hard to get on and off. Just give me my Nike bands and loops...by the way, the new blue Nike loop is really good looking with the titanium case. At an imputed cost of $100, I'm thinking that I dislike the Alpine lop enough that I will probably return this Ultra and get in line for one that comes with the trail loop. Question: is the band likely to be returnable without returning the Watch as well? Apple has had a few different return policies on the bands that come with the Watch, and I'm not sure where Apple is at on accepting returns on bands that shipped with a watch.
Oddly, I couldn't get my Nike sport bands to fit. The Nike loops are fine. It seems like the strap ends are too large for the slots in the Ultra case. Pretty odd, not sure why.
The engineers and design people deserve major kudos for managing to preserve compatibility with the 44mm and 45mm straps. It's really nice not to need to start again on straps.
Bottom line summary: fabulous esthetics and ergos; tall enough to cause some issues; fair price. Overall, if you need the battery life or other features, or just like the look, it's a keeper.