A slipper shouldn't affect pulling away. Under normal circumstances it should behave as a standard clutch. It only works as a slipper when it's supposed to................. preventing the rear wheel locking up.
If you're suffering graunching or bad take up, then it's likely to be the plates. Either dusty, incorrect pack thickness or maybe the addition of a dished plate into the pack would help.
The point at which the slipper slips can be adjusted by varying the pack width. There's a very good article on sigmas site.
There are also two ramp angles which also come into play. 45 and 35 degrees. The 35 tend to be race only.
The other difference is the use of ball bearings or plain ramps. The higher quality slippers tend to use ball bearing ramps as these are smoother.
Although not as cheap as the AT product, there are a few summer specials in the offing from STM. Quality is second to none and there will be a 48T option. Mail me if they could be of interest
