Looks like you already picked up a Yaesu FTM-400XDR, but i'll put a plug in for a different radio for those looking for the same advice you were:
The 400XDR is a great radio and does APRS, but if you want the absolute most full featured APRS radio, consider looking at the Kenwood TM-D710G. It will run you anywhere between $40-100 more than the Yaesu, but has more APRS capabilities and a wider receive range. It also has an actual built-in TNC unlike the Yaesu, this means you can connect your computer/tablet to it for packet data like APRS or a BBS. The TM-D710G can also act as a digipeater. Additionally, you can connect it to a weather station to send out weather packets on APRS. You can have all the received APRS packets sent to an external device through a COM connection and (i think) even via the GPS in/out connection - with this you can set up an external device to show APRS mobile stations and such on a map on a tablet or laptop - or connect it to APRSDroid or similar. There's also a few known modifications to the D710 that allow you to open up the TX range (for emergency situations) and even connect a keyboard for faster APRS message entry. Kenwood also sells a voice plugin module that will read new APRS messages out loud when you when they are received among other things, like 30 second playback buffer.
Aside from the additional APRS/TNC features in the Kenwood, the two radios offer all the same other features - dual band, cross-band repeat, loads of memory slots, etc.
Anyway, they are both great radios, and I had a hard time deciding between the two when I was shopping, but the additional APRS features and the build in TNC sealed the deal for me. My main use cases (aside from, you know, talking on 2m) were to be able to use APRS grouping (to filter packets when i'm in a convoy), send SMS messages and emails from my rig to give updates from very remote places. Things like "I made it to camp", "Mechanical issue, will be home a day later", etc. And the built-in TNC will allow me to connect my laptop/table for more advanced packet radio uses