If you have the money go ahead and buy a diff brace and FTBR diff mounts (front/rear) at least so you can get those out of the way and help some with wheel hop. Remember to remove anything and everything SRA related; exhaust hangers over axle assy, pinion snubber, springs, quad shock brackets, etc.
As for comfort, it gives a much better ride than the SRA and lets the car take turns a lot better.
As for tips and tricks, when installing the IRS make sure when you are jacking it up to install you do it evenly so you can get the front mounts inside the mounting pocket points. Put the bolts in (buy the correct 14mm from ford or buy grade 8 9/16 nuts/bolts and drill out the guide) and let the IRS hang down a litte from the rear so you can get the springs in. Once you get them in then you can go ahead and jack up the IRS and secure it at the rear mounting points. You might have to persuade it a bit to fully go all the way into the rear brackets. Back to the 14mm bolts (or 9/16 whichever you want to buy), make sure and do this since Ford installed the wrong size bolts in almost all 03-04 cobras so there is some play in the lower mounting points of the IRS. These bigger bolts take up the slack but you have to drill out the part of the mounting area (takes 5 min).