I finally got around to watching it, and it was pretty good. Larry Olivier and Mike Caine playing familiar characters in an adaptation of a play - one of those adaptations where you know where Act I ends and you pause the DVD to get up to go out to the lobby. Or the bathroom, or whatever.
Olivier alternately reminded me of Sting and Steve Martin. Other than that, I liked his performance.
I guess that Branaugh remade the move (or re-adapted the play). Olivier's part is now performed by Caine, and Caine's part is performed by Jude Law. I'll be checking that out this weekend. I hear it's not as good.
However, if you're looking for a play to put on for your theatre group, it's a pretty engaging two-man script.