Got mine in the mail today and mounted them earlier this evening.
Some initial thoughts / first impressions:
Snappy! Very positive tactile feedback; there’s no second-guessing whether or not you’ve actuated one of these. “Positive” in the sense that you positively feel the tactility - the tactile style itself is “negative” though, with the bump starting right at the top of the travel.
While I would indeed class these as having a “D-shaped” bump in that it’s big, round, and takes up the majority of the travel, I wouldn’t say “no post-travel” is totally accurate. It’s more like a “D” with a little tail… say, between a “D” and a “P” - but closer to the “D”. So far I’ve only tried one switch that truly has no post-travel whatsoever, and it’s a frankenswitch.
These switches immediately joined my short-list of others on which I find it extra-easy to type with high speed and accuracy. Others on that list would include Box Whites, Kiwis, and Holy Pandas.
The peak force of the bump on these is high enough to wear me out quite a bit more quickly than most of my other switches, though. I might see how I like them with some lube on the legs of one or two.
Can confirm one of the two metal pins on each switch being super dainty. Care is definitely required when mounting these in hot-swap sockets.
A bit of dry-sounding leafy-crunchy noise here and there, but overall more quiet than a typical silent tactile, even in their factory bone-dry state.
Not 100% consistent, but probably above-average in that regard with variances being few and minor. Some leaves make a little more noise / seem to have a little weaker of a grip against the bump, but even those resist accidental presses very effectively and retain a strong, snappy bump.
Folks weren’t kidding; I’m super impressed with how little wobble these have, even putting BOX switches to shame. A few of the switches have a tiny bit more than others, but I bet films would even that right up. I also bet that when the silent linear stems come back to market, these will be the best housings to put them in.
The stems in these are a mostly opaque milk-white, vs the prototype U4 stems I got from Daily Clack having the same translucent look as Halo or Cherry Clear stems. To my eye, the shape appears identical between the two versions. (Edit from the future: it isn’t.)
The “GAZZ☰W” logo is upright when the switch is North-facing, at least on the slot-top versions I have.
These feel a little bit like Silent Box Browns with a rounder bump in that they manage to be impressively snappy even with very modest to light spring weighting.
If I can successfully mitigate the dry-feeling creaky / crunchy leaves in a few of these, I think the Boba U4 will end up one of my very favorite switches. Either way, I’m already very impressed, and excited to start tuning and kit-bashing them.
Edit: some potato photos comparing the previous U4’s I had with the ones pre-installed in my Bobas;
Color. The one farthest from the camera is from a Boba U4, the other I got separately.
Stem legs. Not a straight-on photo so not the best comparison, but it gives you an idea of the shape.
Update: The new stems are definitely not identical to the prototypes, similar as they may appear.
The new stems produce a stronger bump and have less wobble than the prototypes; both in the Boba housings and in others - specifically Halo housings, as-tested. While the prototypes feel a little muddy in Halos, the new ones feel discretely “cushioned” prior to actually bottoming-out on the silicone pads.
While the new stems appear especially dialed for maximum tactility and minimum wobble with Boba housings, I might prefer the comparatively mild experience of putting them in Halo housings.