"Pay no attention to the man behind the curtain".Is foundationless the biggest Beesource hoax of 2010? Gee, who said that six months ago???
Don't let this kind of talk discourage you. There are plenty of beekeepers who have successfully gone foundationless, myself included. It is not a hoax, it just takes a little extra attention on your part and does not fit into every beekeepers business plan.
Is it "easier" to just drop in frames with foundation? - yes, I suppose it is. With foundationless you need to be more attentive as the bees draw out the comb, and expect that with the first few frames they might draw a higher percentage of drone comb.
Since you already have established hives I would suggest making a slow transition this coming spring. As the colonies begin to build up and the brood area becomes congested, pull out just a few frames at a time and replace them with foundationless frames, keeping drawn capped brood comb on either side. Move the pulled brood frames up centered in another box. Continue doing this every week or two as they draw out the new comb. You will not only be helping to retard the swarming impulse by keeping the brood nest open, but your bees will quickly draw out some very nice straight comb for you. This method has worked best for me to get the most uniform comb built out with a minimal amount of attention or comb alignment correction on my part. If you end up with a frame with lots of drone cells just move them to the outside of the box and later they will fill them with honey, or use them as super frames.
As far as natural cell being good for the bees - there seems to be evidence on either side of the argument touting the benefits, or lack thereof, to the bees overall health. Worst case, I don't think it can hurt the bees. It seems more likely to be beekeeper preference. But, excluding any value you may place on your extra time with the bees, it will save you money on foundation.
Good luck whatever you decide!