Not if you're adding on to an existing setup. D44 = US$200, AP2496 = US$150. Adding another AudioPhile is cheaper unless you can get a good price for your used AudioPhile. Also, the AudioPhile is a good choice if you need the SPDIF and/or MIDI functionality.
On the other hand, the D44 is the better choice if you need the +4dB analog I/O.
Only if you're absolutely certain that their internal clocks can be synced together. Otherwise if you're playing/recording multiple tracks across the two at the same time, they will eventually drift apart and be out of sync.