Like others have said, it's a little unfair to assume they're the same price. They ain't!
But, I've used the AW4416 quite a lot (I don't own one, I borrowed it) - and I recently bought
a VS2480 - so I can give a reasonable comparison.
Going on my experience - I would definitely go for the VS2480 (just as well I did then

).
One major issue for me is the number of tracks - 24 being significantly more than 16

Also, Roland's proprietary R-DAC compression algorithm means that you can use all 24 tracks, at 24-bit resolution. In fact, this is the default recording mode!
I also prefer the FX in the roland. Like the AW4416, the VS2480 comes with 2 built in FX processors (however you can buy three additional cards, bringing the total internal FX up to 8). However, the VS2480 has 36 algorithms, and a whopping 250 preset patches. I've found the reverb effects on the VS2480 to be superior to those on the AW4416 (IMHO), in particular. In addition to this, the VS2480 has mic modelling and speaker modelling algorithms - *and* vocoder FX

That was a particular plus to me, the vocoders. It has 10 band and 19 band vocoders, allowing you to send two separate signals into the FX processor (i.e. an instrument and a vocal).
I've also found the mastering to be superior on the Roland - *though*, the AW4416 does have the option of adding the Waves card. I've never used it, but I've heard very good things (though I think it's pretty expensive).
There are a few other things the Roland has, like for example the waveform display feature (*very* useful for editing), the spectrum analyser, and the option to add a VGA monitor. I tried hooking up a monitor to the 2480 - it makes using it a *whole* lot easier! The user interface you get with the monitor is pretty comprehensive and very intuitive, and in combination with the mouse - is incredibly useful.
I wrote up a review of the VS2480 (as well as comparing to the AW4418) on TalkBass.com -
here is the link.