Yeah that's what I've heard from most people. I have a few comics on my Nexus 7 tablet, that I've bought through comiXology. I do agree it's weird, and nowhere near as nice as holding the real thing, however it is just so much more convenient. I have never been that into comics until recently, and using an online store like comiXology to sort and find the ones I want is far easier than going to an actual shop.
The selling point for Marvel Unlimited is it's price, which can't be beat. For the amount of comics you can read for $10 a month far outweighs the real thing. How many physical comics can you buy for $10 these days... 3?