Yes. It's a good machine. The presets are all pretty well figured out and work great in the selected target areas. Not only do I have one, but one of the fellow electrologists at the electrolysis office I go to has one as well. But my particular electrologist uses a Senior II.
The Senior can do 100th of a second pulses, and can vary time for insertion delay and time between multi-pulses. Using this multi-pulse option can really free up hairs quickly. I would consider it bottom of the really capable, fast pro-office machines. They are not new machines (about, what 12 years now?) but they last forever and the basic technology is still accepted as capable of doing a good pro Flash Mode job. If this machine somehow became broken, I would buy at least a Senior II, SX-500, or Platinum. Once you see how extensively one can DIY or co-DIY, or your girlfriend /wife use the machine as well, it becomes very clear $3,000 to $9,000 is money well spent and easily worth it. I mean, doesn't it make sense to skip buying a new car for a year so you can have absolutely hairless, smooth skin? But that's aside the point.
To give a summary answer: The Senior is a great, straightforward, capable machine. If things lack, at least this machine wouldn't be at fault.
Electrolysis, since 1875