Are you saying as well that no one uses the Tascam or that they only use it with external mic pres?
many people use the HD-P2. most people who run mics directly into the unit have the pre-amps modified by Oade. although there are a few people who run mics directly into the stock unit. It is true that many people who run the HD-P2 (myself included) choose to use either and external pre and/or an external A/D.
imo. with the oade acm mod to the tascam you can get away with running mics straight in. I run the oade M148 in front, but have run straight mics in and didn't mind the sound. If yor looking to save $'s start without the pre and add later.