A few things here. My apologies in advance for the wall of text.
First, over the course of the last week I've read all 333 pages of this thread, and am incredibly impressed with the general creativity and positive spirit that has been fostered here. I recently bought a pair of Grado's (Sr-60i) and based on many of the recommendations in this thread put aside my fears and popped the things right open. I have absolutely no regrets about doing so.
Second, although this is my first post on Head-fi, I've been lurking here for about a year. My wallet already regrets this.
Third, I'm sorry to head off from celebrating the return of the guy who started all this wondrous nonsense, but I may have actually found something here.
There was a lot of discussion a ways back about how there must be a sort of 'happy medium' between the jumbos and the bowls, a kind of sweet spot that preserved the soundstage of the jumbos while retaining the mids and forward presentation of the Grado sound signature. I'm not certain I've found it, but I stumbled upon something by accident that I thought worth sharing.
To back up a bit:
Over the last few days I've been messing with my phones a LOT, swapping around pads, opening and closing holes, etc. So tonight I was screwing around, and decided to go padless for a while. This (obviously) hurt a bit, but I was surprised by how radically different the sound was.
To cut a very long story short, when I was putting on some jumbos for some relaxed acoustic stuff I thought of something. I pulled off the headband and pushed the jumbo pads past the retaining ring on the edge of the driver 'inners'-- basically, I moved the pad until the ring was resting inside the cupped portion of the pad. This pushed the driver's cradle a couple millimeters closer to my ear. And then I did the same to the other housing, and listened while holding them up with my hands (since the headband won't fit).
And suddenly the mids are back, and I'm in heaven.
The forwardness from the Grado sig is back in full force, everything just feels 'right' as compared to the sort of attenuated feeling I get from the normal jumbos. But what really struck me was that there was still the same sense of depth that the jumbos provide. The detail and stirring highs given by the jumbos are still there, but not overblown like they were before. It's hard to explain, but sounds very nice, and doesn't seem to compromise overall FR by much (though it'll take more time with these to figure that out).
I think what's going on here is that the drivers are in the same physical position as they would be with the bowls-- IE, the driver cradles nearly touch my earlobes when pressured, etc.-- but the wider bowl of the jumbo pad increases the perceived soundstage.
I've only been listening this way for a few moments, but if this is placebo then I'm deaf. And this is all only on my crappy old mp3s (on vacation away from my home stuff).
Trim down some bowls to "donuts" and sock mod. Does practically the same thing to your sound. Also, it's damn comfy.