Having had all three of the above you mention I am now down to using the Top Peak rack back with the Super tourist rack to clip it on to.
I started off with the Front rollers which are excellent but for me they were not quite big enough, I couldn't get an A4 file in and the clothing run at the start of the weeks commute was a real squeeze! I use the back Roller classics (which again are fantastic) for the beginning of week clothing run or any shopping trips. I have the top peak rack bag on pretty much all the time, it carries my tools, pump, innertubes, lock, wallet, keys, phone etc day to day. Yes the toppeak isn't waterproof but I keep the essentials inside plastic bags rather than buy the overpriced cover! Plus it has the drop down side pannier should i ever need extra space.
Guess it comes down to space and how much you need! One plus of the back rollers is the internal pocket, if they are the only panniers you have then using the pockets for keys etc makes finding them a whole lot easier than the fronts which only have the one compartment.
