I have the Rene2 with the Pam's. The Tempi and Pam's don't cover exactly the same ground. Lugia is right that Tempi is made to pair well with Rene2.

Pam's, on the other hand, also does LFOs, basic envelopes, random voltages (in addition to Euclidian and random rhythm, and all the other trigger stuff).

My sense is that Tempi is perhaps more immediately playable, and works better in live situations, interacting with Rene2. Pam's may be more "structured", and give more options when developing patches offline.