Migrate 6.08 to 7.2 Latest NE

Hello...We are preparing an upgrade from an older 6.08 server running RH 5.0 ES to a new server running RH 6.3 ES Zimbra 7.2 Network Edition with Zimbra Mobile. I was looking at the migration docs and have done it using their suggested 32-bit to 64-bit server migration...However, I came across the ZeXtras Migration Tool and it really seems too good to be true...Would it work in my environment with 120 mailboxes running NE with Zimbra Mobile? Are there any caveats here? Network edition OK with Zimbra Mobile?

Thanks so much!

Dave