The Presonus would have a perceived edge due to the FW interface. Also Presonus has a higher perceived quality while Zoom is considered of lower quality - that is in the mind of those that hold to that opinion and may or may not be true of every product from those two manufacturers.
I think the question(s) you need to ask yourself is exactly what are your needs? Also, are the extras you'll get the Presonus worth it for YOU to make that the way to go? Is the limited DAW control surface capability of the R16 important? Is the ADAT interface of the Presonus important which the R16 does not have? Is the limited sample rate of the R16 a deal breaker - it only does 44.1K and the Presonus does 96k? Are you planning to do most of your work in your DAW to where you don't need the effects the R16 offers? Does the idea of storing audio to SD cards sound attractive? The R16 does this and the Presonus stores to your laptops HD. The ProPack Software Suite that comes with the Presonus would perhaps further tip the scales in it's favor for me personally, but your needs are most likely different than mine. Does that package run on your Mac or is it Windows only? That could make a difference and perhaps tip back towards the R16.
Really only you can answer these questions. With the R16 being relatively new there are not a lot of folks with experience on it to comment meaningfully. I know this 'answer' didn't provide many answers, but you appear to have done a bit a research so far which bodes well. Perhaps someone else can offer more insight to help you further.