I'm really struggling to pull the dps I would feel is adequate. Fights like iskar my dps is miserable on. Not going to profess to being an experienced SP as I changed from disc at the start of Hfc and I'd never played an SP before.
Currently using howtopriest.. Summoning stone and askmrrobot.
Most of my gear was for disc and I've slowly tried to convert it over to SP optimised for Hfc.
Well until you get heroic 2 or 4 set from HFC, those will be more of a DPS increase on fights where you can maintain high uptime on the t17 4p haste buff.
Took a look at one of your iskar attempts from my phone. Youre running cop which is alright but your running mind bender over insanity which is bad. If you run cop you should use searing insanity on the adds dotweave when its st. With your crit you should be running as and dot all the adds and funnel your dp into the priority add. Mindbender also does not give you any benefit for aoe so your losing a lot of dps there.
If you want a comparison you can look up my logs under Djriff on Stormrage.