They both do a good job of correcting the color problem. BUT, the 486 filter puts a strange vinginette of green in the corners on wide angle lenses. The W/A lens looks through the filter from a severe angle at the edges, and the coating of the filter is only designed to be looked straight through. the Tiffen does not have this problem.
If you never go W/A with you lens, you're OK with the 486.

abelcine ...
 

The 77mm T1 will be in on This Friday. Stevie has just sent me a note on this.

Thanks for the reply, I have a filter 486 mounted on EX1 and frankly I do not mind vignetting.Am seen here a test done by Adam Reuter with T1. Never seemed OK in color, has a green tint.

Just got my T1, and am delighted!

Yes, there is some light loss - but I can still shoot inside my dimly lit rooms, so it's negligible (YMMV).

The AWB settled to 2900K with all tungsten around, and the colors are beautiful - with blacks as reach as never before!

bayonette question ref bw 486
 

i have the 486 mounted on the ex3. i also use a wide angled lens that bayonette mounts on the camera (16x9's .45). unfortunatly i have to take off the 486 filter every time i use the wide angle. my question is...is there an adapter that will extend the bayonette mounting capailitied past the B&W 486?

thanks in advance,

Dano

After finally getting my EX back from Sony I 've been able to at last try out my T1.

It does lose a little more light than I expected and seems to desaturate a touch so I would raise the sat about +10 when I have it in. I see now I'd like to have a 486 also as that loses no light and is perfect behind a 35mm adapter where I'm not to keen on losing 1/2 or more stop. Don't think I'll spring for a 486 tough as the cost is so high, but I do understand why some people might want to stay with it. Too limited for a general filter for my taste though because of the wide angle issue.
Best solution - EX1R

why? does the EX1R have a better built-in hot mirror/IR filter?

There is no IR filter on the EX1. The R model added one. Now everyone who buys one doesn't have to buy a lame filter to leave on all the time.