Does the VT-d feature on the i7 have measurable VM gains over the i5 on 2013 RMBP? Some days ago Apple refreshed the MacBooks pro and I'm looking for either well sourced reviews of the hardware capabilities between the models or real world experience to help me value the increased cost of the i7 (3.0 GHz) over the i5 (2.6 GHz) on the new Macbook Pro 13" with retina display (ME662LL/A which presumably will be marketed as an early 2013 model).

I've done some research on Intel's site and, by my reckoning, the CPU release dates / frequencies imply Apple is using 2 possible CPU for the new 13 inch with Retina that ships with 256 GB of storage (which like the CPU can also be upgraded for additional cost). 

Can someone confirm/corroborate that the i5-3230M and i7-3540M are used so that I can rely on Intel's description of the chips or are there other factors at play with Apple hardware. It seems like the GPU of the i7 support higher frequency &amp; the i7 has more virtualization features.

As a regular user of virtualization, does this CPU upgrade offer benefits for VM performance past the incremental change in clock speeds (Intel's VT-d feature sounds good, but I don't understand if it helps existing Mac virtualization software run better or faster)?

I realize no one can make buying decisions, but hoped to learn more about how the hardware works so we all can learn more about what goes on under the hood of this model Mac.
So there are a bunch of comments about the merit of the question which it seems you e taken the time to look at and assess. I'll jump right in to starting the discussion on upgrading. 

Firstly, to be clear you're looking at a new early 2015 13" MBP (I assume you're not interested in a 15", which can support quad core processors and add a whole new layer to the discussion). 

Apple's tech specs can be hard to track down, but it looks to me like you got the same processors I did. The i7 supports a turbo up to 3.1 GHz and 4 MB of cache, with the i5s boasting 2.1 and 2.7 GHz processors and 3 MB of cache. You're right in that the i7 supports VT-d, but you'll need some fairly heavy duty software to take advantage of it. The answer about VT-d is that it really depends what sort of virtualization software you're using, my guess being that unless you want to use expensive commercial software, Oracle's VirtualBox will be the first to support that (though I have no reason to expect this, or know when). 

This brings us to the next level: is the i7 worth it over the i5 (will there be notable performance gains)? For you (and others with this question), probably. The increased cache, better cache coherency, and outright speed increase will be what you notice. Being that all the processors for the 13" are dual core, I was unable to find evidence that there is any significant difference between hyper threading moving up and down Intel's CPU line (unlikely, they all use the same basic core).