I have had the old Matchbox UK paras for a while but was overjoyed when I saw Revell was re-releasing these. I've just picked up a set, as well as the new A Call to Arms figures. These look to me like the old figures that used to come with Matchbox toys.
Anyway, there's a bit of flash on the revell and they're moulded in Revell's really soft dark green plastic. Not ideal. The only issue with the ACTA set are the SLR barrels of the crouching shooters are malformed.
But the main thing is IMO the two sets are actually quite compatible in size. Please judge for your self...