Just picked up this case from T-Mobile US, from their budget conscious brand GoTo:
https://www.t-mobile.com/accessory/goto-define-case-for-oneplus-8-5g
My 2¢/ Pros & Cons.
Pro:
1) Availability, shouldn't be too difficult to find a T-Mobile store that has it in stock, especially with the phone still being relatively new.
2) Fit is excellent, cutouts are precise. The camera cutout extends well below the flash, not a deal breaker, but, I think they should have opted for a more precise cutout for the lenses & a separate hole for the flash. Perhaps this was a cost-cutting measure.....
3) Feel in hand is acceptable, neither the slimmest or bulkiest case I've used.
For feel in hand perspective, if you've used a RhinoShield Crash Guard bumper, this case is slimmer in the grip,a lot more comfortable vs the Crash Guard bumper.
Cons:
1) Price isn't insane, but, I do feel it's a bit much @ $19.99. Sure, it's about 1/2 the price of other cases sold by T-Mobile, but, as everyone here is painfully aware, carrier accessories are grossly overpriced,
So yeah, this case is overpriced vs Amazon/AliExpress/eBay & in a lot of instances, buying direct from the mfg w/a discount code.
2) The volume/notification slider cut-out, while precise,is a bit cramped for one-handed use. Not a biggie for me, I rarely use it, but, for those where this is a priority, perhaps this case is not for you.
Fortunately, the box for the case (at least mine) was not sealed, so, if buying from a brick & mortar store, you should be able to try it out before buying
Misc:
The design of the backside is a bit weird in the looks department, reminiscent of poor 'ol HTC's earlier efforts in the "big chin" look on the front of their phones.
To me, it's not a big deal, but, if I were choosing in-store w/a comparably priced/designed case w/o the "chin'", I'd opt for the other case.
Ditto on the branding of the "GoTo" logo. It's actually not that noticeable, but, again, same scenario just mentioned, I'd opt for the competition.
FWIW, I loathe cases w/branding, as most go overboard w/it, I prefer minimal/unbranded cases, typically one color/material when possible, less is more for my usage.
Would I recommend it?
Sure, it strikes a good balance of form/function (less the slider cutout). If you need a case ASAP for the unlocked or T-Mobile version, it's a worthwhile case.
However, if you don't mind waiting for mail order from wherever you shop online, you could probably find a case that fits your needs at a better price.