I recently picked up a Pyrex RSST as my first rebuildable, despite all of the warnings and the "Should have bought a Kayfun" comments. I could not be happier with my decision.
I was able to get it up and running on my first try and had a ~2ohm coil working well on a plain mesh wick (unoxidized). This worked well on my old MVP at 5v, but wanted to use it on a mech so I scrapped the coil and wound a new one that came in around 1.1ohm. Wow. I've been using the current build for a week and it seems to just keep getting better. I did end up drilling the air intake out to 1/16" as I found the stock draw real tight.
I will say that there will be some tinkering involved to make sure you get rid of hotspots/legs, but I really didn't find it very difficult. There are tons of great videos on youtube of how to build, the pbusardo one is the one I followed.
I picked mine up from Kidney Puncher, they cost a little more than others but open each one up to make sure that everything is in good shape and that there aren't any manufacturing issues. They also have good prices on a variety of rebuilding supplies (mesh, kanthal, etc). I'm currently using 28g kanthal and #400 mesh w/ 50/50 juice. They'll even pre-drill out the air intake if you so desire, but a $2 cobalt bit from Home Despot was cheaper and I wanted to try the stock airflow for reference.
