i would now prefer the roland (can record 24Bit / 96khZ) and it´s a bit smaller then the tascam + has a bit more solid metal housing (Tascam = plastic box)
i have the DR-07 recording with CA-14 Mics with preamp via line in, maybe better choice on very loud shows... but you can do this on the roland also. But i´f not found if the Line In Gain is adjustable like on the Tascam.
Battery running time not a problem - using the Tascam with eneloops ...