Well personally I love the rotating 5% categories and wouldn't dream of changing my 5% Freedom to a 1.5% Unlimited. 1.5% is always useless to me since I can get 2% with the Citi DC. So my cards have to at least match or exceed the 2% on a transaction to ever get swiped.
I could see someone wanting it specifically due to the UR points, but as I've often mentioned (I'm sure you guys are getting tired of hearing it
), I don't travel so I only take cash back anyway, and I couldn't care less whether the cashback is from Discover, Citi, BofA, or Chase. Wherever will give me the most cashback is where I'll go.
Personally, I also do find it useful to have both the Freedom and Discover It and have always loved the combo. Of course it's most useful when they don't offer the same category at the same time. There are always some I don't use AT ALL like gas/travel, home improvement, movies/entertainment, but by the same token there are always categories I love like restaurants, online shopping/amazon, and groceries. As long as those categories don't sync up I can get 6 months a year at 5% on them. If they do sync up it's a lot less useful, but occasionally I do exceed the $1,500 quarterly cap on one so there's potentially still a small benefit. I don't personally find it difficult to keep track of the categories or much of a hassle to switch which cards I'm using for which category.
I'm just hoping they don't eventually completely axe the original Freedom and force people to convert. If they did, like I said I wouldn't have much reason to keep the card...well unless the DC gets nerfed, which I'm sure it will be at some point, and I can't find an always 2% alternative.