I agree with this.. I'm not a big fan of the paddle switch.. for any prolonged use my hand cramps having to hold it down.. I'd prefer a simple on/off, but I got it on clearance when I bought it, so I'll just live with it.. not like I use it everyday, so in the rare cases I pull it out, it's a minor annoyance.... knowing this now, if I HAD to buy another, I'd go with the switch if it's an option.. the grinder can get held in some awkward positions to reach what you need, the paddle gets cumbersome to keep pressure on it sometimes .. that said - I do like being able to shut it down without pulling my hands off, so I can see the progress.. makes the short 2 second "stop and look" easy, without having the grinder constantly on.. can't have it both ways though..
But to answer the question, yes - you have to keep it held down to run. Releasing pressure shuts it down. There is a second safety switch to be able to engage the paddle. So it's not like if you set it down, it can accidentally turn on. But once it's going, if you release pressure slightly it'll stop without having to engage the second switch to start it again. There is no trigger lock to keep it running either - pressure must be maintained on the paddle at all times..
It's really not THAT bad.. a decent rubber band can cure it all, if its really an issue with prolonged use.. with a 4.0 battery I think you'd get about 20 minutes of light/ moderate use out of it..