Ran the test build - here is the subjective assessment. It feels better than before (judging from textboxes (clicking them away), it has a little less input lag than 1.54 (release build)), but it still feels less good that 1.52.
On the "feels" scale, so highly subjective - and would probably not survive a double blind test.
I've uploaded a test save which I used to assess the build.
http://www98.zippyshare.com/v/kPkhaFwz/file.html
Its for md_shadowrn - shortly before the end of the game, so if you dont want to spoil yourself the game, I guess - dont use it...
Here are the responsiveness tests:
1. from the save location, press d/r (down/right - diagonally) on the joystick, and let the characters move (fast) through the area, while the entire area is scrolling. Diagonal movement speed on the characters is a little faster than non diagonal - try to stay diagonal. if you hit a obstical switch diagonal direction. Switching direction with the analog stick is also a little test on how instant the on screen characters will switch in their little walking animations (walking direction).
Subjective assessment - there are moments that feel like there is a slowdown in the screen scrolling, compaired to 1.52
2. from the save location, enter the door near by (left). After a little dialogue, this teleports you to the last short mission of the game. On the dialogue boxes you can check input lag, they are supposed to switch to the next one instantly. After the teleport, move up - and shoot at the enemies that spawn (A button to shoot, B button to switch target), on reaction. This feels extremely off on the 1.54 release build, a little less so on the test build, and "best" on 1.52.
Continue moving up and through the open doorframe - and you will trigger dialogue and the boss fight. Dialogue boxes again can be used to assess input lag. To get through the boss fight mashing A should be sufficient.

- after he is done, more dialogue , and a video sequence - with more dialogue. Both feel off on 1.54, and a little better on 1.54-1, but still better on 1.52.
What made me realize that there was a difference, was the scrolling speed of (1.) while diagonal walking. I've played the game for about 30 hours, and the instant I loaded it up in 1.54 (release build), it felt wrong.
Also - I did about 20 test runs, through all the builds - to assess what I've just written. So at least this isnt just "first impression" stuff.

edit: Renaming the test build to 1.54-1 helps, btw.
edit: Also test build crashes more often (during or shortly after startup). Just had a crash after the "scanning roms screen. Thats a first.
