delay when adding new recording is currently because of unoptimized accesses to DB. It depends on number of channels, number of existing schedules, number of TV Tuners etc. There is a patch that greatly improves this (in my case from 25 seconds to 3-4 seconds), but it will be included (hopefully) in later versions of MP (1.2.1 or 1.3). So don't hope to get it faster with changing DB engine.