Probably work OK for someone a bit tech savvy, but as you say, not really family friendly. A couple of things to consider.
First, there dis no guide available beyond the limited channel info provided on an ATSC signal. These boxes are time based recording, like old VCRs and are not name based recording. It will not adapt to changes in schedules, so you must stay on top of any changes and fix the timer.
Second, there is only 1 tuner for recording. Boxes like the Roamio have 4 tuners.
Finally, both of these boxes need external hard drive storage, which is not included in the price. This will add $70-100 to the final total price.
None of that is a deal killer, just stuff you need to be aware of.