Not having heard the grados (which I hear aren't so hot for bass) I can say that the MSR7's produce really really nice vocals mids yet still have great bass (that ends up surprising you - especially after you burn them in a bit). They are accurate and sensitive. Perhaps too accurate. I wouldn't say that "weak" is a fair or accurate description ... Perhaps "neutral" is fair... You're gonna hear the recording for how it was recorded with the MSR7s. There's a few songs I used to love but now don't because of some the hidden details (and imperfections) that are now exposed with the MSR7s.
You'll hear people saying the MSR7's are a little sibilant. I see what people mean, but I also realized it was the recording that was sibilant. Other recordings that had better production, better de-essing, didn't show that sibilant characteristic. Other headphones hide that better, but the MSR7s don't (good or bad is up to your preference there - but the sacrifice is at the benefit of better, more accurate, vocals).
As you'll undoubtedly read with the MSR7's, they are "near" reference quality. You just hear everything. Whether or not that ends up being a positive thing is up to personal taste. It also might mean you start going down the path I did with tube amps looking to find a good match that colors sound in ways you (and you personally) enjoy. Again because they are sensitive and "neutral" you can impart different qualities on them easily with different tubes. Whether or not you want to mess with all that is a whole other story.
I would certainly love to try some Grados, but I like having closed back headphones for work. So at the end of the day, things like that may also be a big factor on your choice. All I can say on the matter is I love vocals and mids with the MSR7s. Especially with ODAC + tube amp. I'm still in search of tubes for the bass department.