No. Try out the 4 gig, if you find it a little sluggish, buy 4 more from OWC.
the cheaper one takes up all available RAM slots, hence the four 2gig sticks, ie. 4x2=8.
The more expensive version only takes up 2 RAM slots, two 4gig sticks, ie. 2x4=8. This option leaves the other slots open in case you want to upgrade to 16 gig without buying all four stick again.
Depending on how far in the future you should decide to upgrade to 16GB, this could actually work out to be
considerably more expensive.
Working in wonderful pounds here. It costs £480 to upgrade to 8gb, 2x4GB.
This is also at the cost of the pre-existing 2x4GB which Apple charge, quite clearly, £160 for.
So, total cost of 2x4gb is actually £640.
Crucial.com list this same kit at £459.99. For the sake of argument let's say you could sell the stock 2x2GB on Ebay for £40. This brings the price to £419.99 for 8GB. Or £60 cheaper than Apple's RAM.
Of course, if you value your time this is an entirely worthless observation because the effort of ebaying and installing RAM could easily account for the difference.
However. £67.85 will upgrade you from the stock 2x2GB to 4x2GB which leaves you £412.15 better off.
Now, right now 16GB will set you back almost £1000. But I'm pretty sure that by the time you actually need 16GB you'll be able to get it for less than £412.15. Assuming, of course, that you haven't simply replaced your computer by then and thus saved that entire amount. If you DO upgrade, you've then got 4x2GB spare to give away, sell, turn into geeky jewellery, or eat.
What happened to the i7 being triple channel, anyway!?