For $100, I think it's worth it.

(1) You'll be able to get the free EC seats at 24 hours (your results may vary, but these have always been available to me as an FO at 24 hours, I've never had a case where EC seats are unavailable at that time). Assuming EC costs $20/flight, you get your $100.00 back over only 5 flights.

(2) One free checked bag in 2014, of course. Four checked bags over the course of 2014 makes $100.00.

(3) If you fly 25,000 miles in 2014, you'll get an extra 6250 Delta skymiles with the 25% Silver bonus. Assuming each skymile has a "cash value" of $0.01, that's $62.50 you make up right there.

(4) You will be taken care of much more in case of IROPS in 2014 as a Medallion, even if only a Silver. A great intangible benefit.

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The 6 extra flights will take extra time, of course, and you're running the risk of weather/cancellations/velociraptor attacks at your connecting airport that would REALLY increase the amount of extra time, but I'd still do it.