Firefox Slowing Down?

Andavari posted here about Firefox 39.0.

http://forum.piriform.com/index.php?showtopic=34708&page=28#entry264150 
I upgraded to 39.0 also.
This is a fairly fast desktop, all other applications work quite fast.
It is win xp, AMD Athlon 64 X2 4800+ dual core processor, 4 gb RAM, actually uses 3.3 gb.
Browser slowed to a crawl, showed huge resource usage. IE8 is faster!
Seems Firefox is getting slower, so I went looking for faster browsers.
Found 3 that function well and fast here: K-meleon, Maxthon, SeaMonkey.
Midori works OK but not as well.
Maxthon and Seamonkey have portable versions, could not find one for K-meleon.
EDIT: Found the portable version of K-Meleon, its on the same sourceforge page as the regular version. :wacko:
Are any of these four known to be unsecure or bug ridden or anything like that?
Thanks
Sadly, Opera 12.17 always freezes after a short while, and Palemoon locks up and requires a hard restart.
Have not tried the newest Opera or the newest Vivaldi.

I use SeaMonkey on a Win 7 machine.

I like it and have no issues with it so far.

(never used Firefox as a browser, none of my machines like it :lol: )

For me it is significantly faster than the previous Firefox Portable v28.0 I was holding onto forever. One of the main reasons I even updated was for faster speed.

Perhaps it's your Firefox profile (my old profile worked fine), or add-ons. Usually it's the profile which has to start anew to remedy any speed issues in Firefox.

OK, Andavari. Thanks. I had been pretty much updating as I went along, and noticing that FF seemed to be slowing.

I use the portable versions, sandboxed. That may also slow it down a bit.

One thing I just remembered was that old Firefox Portable v28.0 was a clean "install", and I upgraded over it to Firefox Portable v39.0, so only one update and one profile change I've had since v28.0 - which could've been why I didn't have any slowness issue.

I have been using Palemoon for about 3 years, no lock ups ... but I agree with you about Firefox ... it has got slower and so many features are not finished.

i hope, mozilla "featured" not broke itself with the features...