I can see how they might be OK for a suburbanite who just wants to trim around flower beds, bushes, mailbox, etc. (and they're quiet which is nice) but yeah, most of the trimming I do is brushier stuff or for extended enough periods where a battery might not hold up too.
Same for HF's (or anyone else's) AC powered pole saw. Almost none of the trimming I use one for is anywhere within extension cord range of an outlet, and don't really feel like lugging a small generator around. Again, maybe good for suburbanites but less useful for us rural folk. :confused3: