Someone may have answer for me here too. I was able to put full gradient across a page by just stroking "after selecting the gradient" of course. Now I am not able in this version, or have forgotten what I need to do?

I investigated a bit more.

I decided to give a try to the "semi official" (semi as i think i have read the GIMP devs never release a window version themselves) 2.8.4 release from there :
http://www.gimp.org/downloads/

As expected it removed my trusty 2.6.10 (but fortunately i backed up everything before so i can reinstall without a problem) while installing.

Then i launched that 2.8.4 and tested with the same condition painting.
And ... it's as smooth as your win32 build of 2.8.2 was.

I re-installed your build of 2.8.4 to see if by some oddity having installed the semi official 2.8.4 would have changed something, but no.
Your win32 build of 2.8.4 is still very sluggish when painting in the same condition as i tested.

Having absolutely no coding/compilling knowledge, i have no idea why it is happening, what is that different between your build and the semi official one that is responsible of this very noticable performance drop (that didn't happened on your win32 build of 2.8.2).

to SallyAnne
I tried and the behaviour is correct as usual; I tried two different situations:
1 - creating a new image, selecting a gradient and drawing with the pen
2 - having a picture already on the screen, adding a layer and drawing on the new layer
In both cases I got the gradient correctly painted over and with the correct direction given by the stroke direction
my environment: win 7 32-bits gimp 2.8.4

oh dear, my mcgimp was crashing tonight. It was when I was trying out layer effects bevel and emboss, and decor chisel. I was making buttons, and it seemed ok for the first one, but started crashing on the second one. The filter would not behave so I had to force quit the script-fu folder that was in my dock. It emptied out my script fu scripts and some of my regular basic filters. Very odd. I got them all back when I closed and reopened mcgimp, but the same thing happened again. Seems like when I am done with a script fu filter bevel and emboss, it doesn't close and I cannot close it with out force closing it.

I found that out, I was trying to get rid of script fu but I found out that it doesn't hurt anything to just leave it behind there as I work. I see also, that every time I use a different fu, it doesn't close, just hides, so you can end up with several little fu windows behind my gimp window. I can live with that, now that I know they can be there with no problem! So all my problems were because I was trying to get rid of the windows when I didn't even need to!

@partha:
Question about your dark theme in 2.8.4 portable (named default), I'd like to know its real name and its license to check out if building upon for re-release is okay.

Few more questions about your build, still concerning gtk theme customization:

I see that you provided many gtk engines dll, most of them being registered as late 2012 (also a now working aurora dll, which is great !), so, did you compile/port (don't know the appropriate word here) them yourself ? Because most of my dlls for these engine are from 2009 or older.

Also, because I'm testing different widgets, I'd like to know if it's safe that I bring older engine dlls to your build, I thought about nodoka engine as this one not included, but it's from 2009.

@partha:
Theme subject again, I was wondering why your build successfully detect any dll engines while sourceforge gimp stays blind, I mean did you torture them or..