I like the DB-01 a lot; it's great fun all by itself. I don't think you need the Pexp-1 just for that; the DB-01 is based on a Eurorack module, and takes clock in (just a regular Pam's channel), as well as pitch, gate, and filter CV in. Its output is hot enough for Eurorack and doesn't need boosting, if you want to take the signal back into the rack. I don't have experience with the other things you mentioned, though people seem to like the Beebo a lot.
-- plragde
NICE!!! Just sent one email for a refund of the PEPX1, hope they return without any hassle.