I think you have to look at the value of the EMH in terms of dollars. The EMH gets you the maximum touring efficiency during any part of the day...and also gets you an additional hour in the parks (if you use it), however, you can still get very good touring efficiency during the first hour in a non-EMH park. If you are basing your decision on where to stay SOLELY on the ability to utilize the EMH, you have to consider what it's costing you. If you are spending $400/night to stay at DLR when you can stay off site for $150, that EMH is costing you $250. It is worth $250 to have that hour? That's up to you to decide, but I think we know what the logical answer is. If you want to stay at a Disney hotel and don't mind spending the extra money, then the EMH is simply a perk that you can take advantage of.
But here's the way I look at it. Disney is charging you $300-$800 per night to stay at their hotel and encouraging you to buy multi-day park tickets, which you are spending additional dollars for. So if you book a 7-day stay with a 5-day ticket, you are essentially paying Disney $300-800 per night for 5 of those days to basically sleep in a room. Granted, you might return to the hotel for a few hours to take a break and use the pool, but you can do that at an off-site hotel also. If you were to stay at the BWPPI, for instance, you're looking at about $160 per night, you are closer to the park entrance than any Disney hotel, you have breakfast included, and you are saving all those dollars. Again, it is a question of "What's the EMH worth to you?" and "What's the experience of staying at a Disney hotel worth to you?"