I have used a Grohmann #4 traditional grind as one of my primary outdoor knives for the last few years, and I can recommend it without any reservations. It's a wonderful blade design, with a comfortable handle and excellent general capabilities. I haven't encountered a problem with edge retention. It's a relatively thick blade, so you won't be getting the same sort of edge that you would see on a Mora or even a Becker, which means that it doesn't lend itself to 'hair popping' sharpness. Nevertheless, it goes through wood, meat, and everything inbetween without any problems. You can also order a flat grind version; I don't have experience with this type.
My #4 sees a lot of use in food prep, where it is the perfect size and shape for most tasks, either in the kitchen or the campsite. The design of the blade means that you can slice effectively without worrying about contacting the cutting board with your finger.
My only complaint (if you can call it that) with the #4 is that the sheath retention strap can be scored by the knife edge when drawing. It's a wonderful sheath design, and very comfortable, but I'm concerned that a few years of consistent use - and I really use this one a lot - will lead to a severed retention strap. I don't know how this could be avoided, though, and it's probably easily fixed down the road.
I hope that helps, and I hope that you enjoy your Grohmann. I recommend the classic #1 design as well. If it weren't for the looks I'd get, this would easily be my first choice for an edc knife - and it's a beautiful design as well.
All the best,
- Mike