I'm looking for a few filters to fill in a couple of gaps. It seems the only people that currently make them [#12,15 and 21] is Tiffen. Some come close. B&W makes what they claim is a #22. Just how good/bad are tiffen filters?

I've got the various filters in 3x3 gel format but would like to get them in glass. Tiffen is now making Kodak filters so they can't be that bad can they?-)