I have looked at both, and a buddy actually is letting me use his countyline (TSC branded KK) now. The Frontier only has three scarifiers vs. the Countyline having 4. I am not sure how much that matters. Both boxes appear to be the same gauge metal. The scarifier locking pins and setup are a little better on the Frontier. Both blades have a decent finish and appear to be constructed well. The Frontier is hands down engineered better on it's 3PH mounting hardware. The crimped trapezoid engineered mounts on the Frontier appear to be hands down stronger than the 1/4" x 2" flat iron that the Countyline uses for connections to the lift arms. I have noticed that the Countly line I am borrowing has a bent mounting arm on the lower right lift arm -- Nothing that is stopping progress, but just something to note. I think it would be helpful if Countyline would have either shortened up its mounting points between the implement and lift pins or put a spacer bar between the two lift pins to effectively double the strength of the mounts from any side torque. The Frontier lift pins are very close (4-5") from the implement. The only plus side I see to this is that if there has to be a weak piece, that is the piece I would want to bend rather than breaking a shank or the tractor. For $20, I can buy another piece of stock, drill two holes, and be back in business.
I do not believe the CountyLine is iMatch compatable, but that is not a big deal to me right now nor for this implement.
Another concern, although I think it is small, is that if I need to purchase a replacement blade, I know Deere will always be available, Countyline....not quite sure.
Still a tough decision, but borrowing (which I hate to do) is making me think that the Countyline will do for what I need especially since it is only a couple days a year tool. It would be nice if it was green...
Right now, I can't do much work as the rain has been killing us. Working the ground is pretty close to impossible.