Not really the point of my post, but. . .
What are the primary reason some would modify a Grado? (Or any headphone for that reason) I would say that at least 80% of the time or more it is to "enhance" some aspect of the headphone. What other $200 headphone do you know that comes with cheap vinyl headband, plastic cans that everyone wants to replace, and earpads that many seem to not be able to stand? When I spend $200+ I honestly feel the package needs to be "complete", thus making any modifications feel less of a necessity and more of purely a personal option.
...and that is precisely what modifying is, a personal option. People dont modify their Grado's because their lacking. The SR60 for example is highly regarded as one of the best headphones for under $100 you can buy. So for amother $150 or so you can have a sub $250 phone that sonically is way better than the plastic version you started with and cosmetically is unique, persomal, and awesome looking...but you have to be willing to get your hands dirty, pop the hood, and turn some wrenches so to speak.
I modded my SR60 after I got my HF2 which was a complete package like the RS1 is a complete package. The bigger picture here is if you improve the enviroment the driver is in, wood versus plastic. You improve the sound quality, and if you take into consideration the tonal characteristics of wood, the same way a luthier does when he custom builds a guitar then you are also customizing the tonal qualities that your trying to get out of your headphone. The bottom line here is your headphone is pretty much nothing more than an air pump. So pretty much all your doing when you modify your headphone is modifying the way that it pumps air, which is one of the reasons for an amp.
Grado makes a good product. Any one of their phones right out of the box has plenty of value, the $200 one is generally considered the biggest bang for buck Grado available. If you dont like the Grado house sound though it's sort of a moot point. I on the other hand happen to love both stock Grado's and if it's modded, all the better.