I've never used the Empress, but it gets good press here by lots of people.
With the SL20, you can tame the stuttery effect by balancing the effect level and direct level accordingly, and also rounding off the attack using the relevant knob.
http://www.bossarea.com/other/sl20.asp
It is a one or two trick pony granted, but it can be really creative when combined with other effects.