I don't know the cfm ratings for the two, but a quick glance at the specs show that they should be similar. I would imagine that the biggest difference between the two would be the sound and possibly the longevity.
Out of curiosity, are you piping the whole exhaust to 2.5" or are you just going to do a lunchbox delete and finish it like this? My reason for questioning is due to the fact that you won't see a performance gain if you go with the latter of the two. If performance is what you're after, then you'll need to open up closer to the cat.
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