As a helpful emailer just reminded me, the Galaxy S6 officially goes on sale today in the United States. Anyone who’s read our Galaxy S6 review already knows what I think of Samsung’s latest Android. With the possible exception of the Galaxy Note 4, it’s the best flagship Samsung has ever built: a glass-and-metal wonder with a delicious display and an outstanding camera, held back only by its battery life.

And maybe some of its software, too.

Here’s the thing. After a week of use I was calling the Galaxy S6 (SM-G920T) one of the most responsive Samsung phones ever. Compared to some of the company’s other Android products –notably its always-overburdened tablets– the S6 was a dream, with smooth slick transitions, quick animations, and a camera launch time faster than almost anything out there. But over the next few days, that responsiveness began to ebb. Frames dropped in animations. The phone was slower to redraw the home screen when closing some apps. And even the sporty double-click-to-camera launch shortcut started lagging. While not everyone I’ve talked to has replicated all of these specific shortcomings, I’m not the only one who’s noticed them.

I tried a bunch of stuff to pin down the source of the slowdowns: disabling T-Mobile’s bloatware; routinely closing all apps; restarting once per day; running on WiFi only (and then cellular data only). All to no avail. And then someone on the above podcast suggested that my predilection for using Samsung’s new theming engine might be the problem. Had I tried reverting to Samsung’s “Default” out-of-box theme to see if that solved the problem?

Ugh.

Of course, I hadn’t. The minute Samsung told us we no longer needed to rely on a third-party solution to escape its … unfortunate software aesthetics, I jumped ship. First to the Avengers theme, then to Space, then to the more minimalistic Purple, then to Along the Path for a relaxing virtual jaunt in the countryside. Finally, I settled on COGUL_Black, a wireframe theme with just the right amount of TRON-like flair.

Ahh.

But while my eyeballs rejoiced, my patience didn’t. I found myself … waiting for everything. This persisted no matter what non-Default interface paint job I chose to use. While I didn’t make the connection myself, the helpful podcast suggestion above led me to believe that the Galaxy S6 theme options may indeed be slowing device performance. Earlier this morning I reverted to Default, and it’s been smooth sailing ever since.

Now I need your help to determine whether my own case is a fluke, or demonstrative of a larger trend. Judging by the comments, a lot of you were champing at the bit to pick up a Galaxy S6 of your own on launch day – now that that day has come, maybe we can crowdsource the solution to this puzzle. So, newly-minted Galaxy S6 owners, please see the poll below! Run some experiments, cast your vote, and then head on down to the comments and let’s see if we can all crack this nut together.

Galaxy S6 Review Video

… and just in case you’ve forgotten our position on the Galaxy S6 as a whole, here’s our video review as a refresher: