Just sold my MS-1s and got SR-325s, but I spent nearly a half year getting carried away with different pads on the MS-1...
::. Comfy
Comfy pads excel at nothing. After using C-Pads, I scoff at their namesake
Sound is veiled; the cans are being held back.
::. Quarter-Mod Comfy
For those on a budget, this helps. Less veiling, more clear mids and highs. For serious listening, look elsewhere.
::. Bowls
Damn! There's that signature Grado high end I kept hearing and wondering about. It's charming, and mesmerizing on certain material. But for all the magic in it, I'm afraid I find it fatiguing, like smacking mosquitos out on the lawn while at a Zeppelin concert.
::. TTVJ flats
Wham...impact up the yin-yang. This is fun listening. As a youngin, I always used to cup my hand and press my cheap headphones tight against my ears to feel that muddy bass slam. This is like that, except not ridiculous. Sounds better too. Only problem is you lose some soundstage and high-end sparkle. Still, they're my favorite of the 'standard' Grado pads. Warmth and musicality abounds. Swipe that credit card quick before you look at the cost.
::. vwap flats (modded senn-414)
A compromise some may love. If you can find 'em. Same class as TTVJ flats, but missing that final 10% of thump and warm. Shame, a lot of the magic seemed to be in that 10%. But rejoice, the mids and soundstage are kinda-sorta improved! Little comfier too.
::. Headphile C-Pads (Alpha 4-port)
Big puffy attention-drawing awesomeness. Soundstage & airiness is turbo-injected. Possibly too much, but usually a nice improvement. These things have a comfort level that is head-and-shoulders above all the others. Sounds like TTVJ flats (deep warmth), except more clear midrange and less veiled highs. I got a ported version, with little pegs that you can plug holes with to change the sound. This drives me nuts, because every permutation has different strengths. If you can find a nice pair used, jump on 'em! Easily justifiable price if you're planning a future Grado upgrade, and/or own a masochistic wallet.