It's really sad that I have to answer my own question, but here it is:
The Petite Thrusting costs less than a third of the Stronic Eins, is not as powerful, has a horrible control panel (for three speeds and one program for each part of the toy) and is made from TPE. It takes rechargeable batteries.
The Stronic Eins is amazingly powerful (and heavy), is so big that I need to be well warmed up before inserting it, has wonderful, easy to feel buttons (which you need to scroll through all the different programs) and is made from silicone that attracts dust like crazy (really, you'd need a cleanroom to use it in) and needs LOTS of lube. The Stronic Eins gives the impression of a Mercedes car - the Petite Thrusting of a Fiat 126...
But the sensations the two toys provide are amazingly similar.