I haven't heard the latest (iirc it's now the "i" series...) iteration, but I have owned a few Grado sets over the years and still have the SR80's I bought in 2001, though they are a bit of a "trigger's broom" as I've replaced the foam pads a couple of times and the drivers now dangle from aftermarket metal gimbally jobs and the headband is a little less sparsely padded, but same drivers, same ridiculous captive cable. And the same addictive, energetic sound.
They aren't perfect, but some judicious EQ sorts out a lot of the less appealing traits.
I've had PS500s - never got on with them at all - and SR325s - sounded like more exciteable '80's but heavy and with the most unpleasant foam pads and I couldn't find enough gains to keep them over the trusty old 80's.
I've also dipped brefly into the Grado replacement driver/wooden cups diy scene but never got anything like good results.
The old SR80's are not my go to headphones but they do get used with my pc music and Yamaha synth and occasionally they come with me on trips.
Great headphones in their own way and they do so many things well compared to some very expensive headphones.