The Kombi system works pretty well, I think. I have the KM55 and the KM130 and find for certain things that one works better than the other and visa-versa. For instance, if I have some tree trimming to do I usually want the 55 since it's a two stroke and spins the chain faster than the 130. However, if I'm down in the gully trimming really hardwood (like Osage Orange) then I want the 130 since it has grunt that the 55 doesn't.
The string trimmer is pretty good; I've heard unhappy comments about the inability to feather the throttle on the 130, but I find that isn't the case for me; it works fine. It has the grunt to get down in the ditches or clear tall standing brush - most of the time it's on the rev limiter. It also is very torquey at low revs, so in close you still have the power to do the work without marking up the bark or siding or paint. It holds more fuel and is a bit more efficient than the 55 so I can trim the whole lot and the ditches without having to stop and refuel. On the other hand, the 55 is lighter and for quick work around a set of trees or yard-obstacles then the 55 is the better suited. Hope that makes sense. I use the Super-Cut head on the straight shaft; I like it because I can wind line on it and never touch it again (no tapping or fiddling with line) until it runs out. Also kids figure out that they can tap out all the line and then have a break! The blade works very well with either power unit.
My wife uses the cultivator in her garden; she hasn't said which power head she prefers but she seems to like the 130 which is easier to start (one pull, literally, yank it and then flip the choke off quick-like and it's going).
I don't have a blower or sweeper attachment, but of the attachments I have the one I like least is the edger. It's uncomfortable to use, doesn't work as well as I'd like and if it I had to use it more than about twice a year I'd sell it on CraigsList and go get a unit that has the engine on the ground and rolls.
I'm not running a yard service or anything, but we often will load up and go mow for one of the widows or old maids in the area so the machines get a workout and we've learned what works and what could use some improving if you take my meaning.
And last Summer I bought a bent shaft trimmer for my oldest kid - she wouldn't get with two feet of anything when running the rider; it was taking forever to trim. She hates it so she's inspired to be a much better mower. Best $75 I've spent on OPE in years even though it almost never gets used! She knows if she does well mowing I'll do the trimming and she won't be bothered.
Overall, I give the Kombi system two thumbs up. If I were forced to have just one power head the 130 would get the nod; ideally though, one of each allows you to select the best tools for the job at hand. Note that I didn't go out and buy all these tools on the same afternoon!
