The Baggs I-beam system uses a bridge plate transducer that attaches to the underside of the bridge - so the saddle is of little consequence.
There are many good pickups out there at the moment - the K&K pickups are similar in that they also attach underneath the bridge.
Both are very good systems - I opted for the K&K Trinity which combines a internal mic with the underbridge transducer. It is a very nice system indeed.
Fishman have split saddle active pickups which are quite nice and very straight foward to use.
It's difficult to try these things, but from what I can tell the Baggs and the K&K systems are the most highly thought of.