XP x64 and software (particularly Firefox+Thunderbird) ?

[Defenestration]

I have moved to XP Pro x64 SP2 through necessity and am trying to achieve maximum benefit through all the apps I use. Most of the apps I use happily work under x64 running as 32-bit apps, but some do not. However, the more native apps I can get running, the better!

Two apps which I use all the time are Firefox and Thunderbird. While Thunderbird wouldn't really benefit from an increase in speed, Firefox would. As there is no official native x64 build of Firefox available, I've had to look around and come up with:

The original Daddy of x64 builds: http://www.mozilla-x86-64.com/download.html

AND

The provider of stable x64 builds: http://www.vector64.com/WindowsBuilds.html

As x64 compatibility requires a few mods to the original source code, I'm wondering if anyone has looked into the security aspects of using these x64 builds (ie. rogue code) ?

From what I've read the x64 version of FF is much faster than the 32-bit version, hence my preference to use it.

Should I be worried about using x64 builds of FF and TB with regard to security issues ?


PS. Why don't Mozilla support Windows x64 ?

A. I guess it's the age old problem of an entity becoming too large to see the future (ie. 64-bit OS's) and what's really important. Oh well, FF was a good idea while it lasted (just like Netscape used to be)

[WSFuser]

Unless you mean its memory appetite, Firefox wouldnt benefit much from having a x64 build. When I tried x64 Windows, I just use the normal build. Seems fine.

[Defenestration]

I have read that rendering speed is improved in the native x64 version of FF, but haven't tested it myself. I've no urgent need to use FF x64, but wanted to check on the security aspect of mods/builds made by an unofficial source.