This is a very lightweight weedeater, which has an extendable shaft. Both of these things make it easier on the back than my last weedeater, a Black and Decker. The detachable battery is also good, as when the battery is no longer effective, as is inevitable, it can be replaced, unlike my Black and Decker. The charge last 20-30 minutes, also better than the B&D, and it cuts grass faster.
By some quirk, the screws needed to attach the safety guard were not shipped, so I tried it out without the guard attached, and I like it much better that way. You DO need to be MORE CAREFUL if you don't attach the guard, as more debris is shot out farther. But, if you keep kids and animals away, wear long sleeves, long pants, shoes that cover your whole foot (no sandals) and eye protection (I use an old pair of big-lensed glasses), you should be fine (not to mention, if you don't have rocks and twigs in your yard, as I do, you won't have this problem. You're not going to be hurt by the flying grass).
The upside to the guard being off is that you don't run through the string as quickly (since it's not being cut off every time it hits the guard, and you can cut a wider swath of grass.
The spool that holds the string doesn't hold as much as the B&D, but since I tend to buy a large spool of the stuff to wind onto the old spool rather than buying the replacement spools, it doesn't bother me.
I've read reviews on all kinds of weedeaters where people were disatisfied with the way the string automatically "dispensed" from the spool (on the no tapping models, like this one), and while I understand their frustration, no string weedeater of either kind is going to be perfect. You will always have to do some tweaking from time to time. Just expect it, and you'll be a lot happier.