I have an RNP, Digimax LT and recorded in a studio with the Octopre. The Digi LT is a little thinner and less detailed than the RNP but should be fine for what you want (toms, etc.). I like the LT because it has no limiters, does have an insert on each channel so you can use it as a pre w/ digital out, pre w/ analog out, or bypass the pre and use as an a/d converter, and is cheaper.
I haven't done a direct comparison between the Octopre and my units but when my band was tracking it was used as 3rd string pre (Behind 4 API's and 2 Hamptone tube pre's) and it sounded fine. Most shootouts I've read between the Digimax and Octopre say they are pretty close in all areas.