There's nothing wrong with a tankless water heater, and for the OPs use case is probably a very good fit, my guess is those saying to avoid them have never used one, nevermind owned one. Maintanence on them is minor, depending on usage and most importantly water quality, they do need to have the scale flushed out of the heat exchanger periodically, I'm on a 2.5 year schedule with mine. Flushing consists of hooking a small pump up to the ports and pumping a $20 bottle of citric acid through the heater for an hour, this is a task well within grasp of many homeowners. Scale buildup can be greatly minimized by decreasing the temperature though, because it is on demand the water supply can be reduced because storage isn't necessary. 120F is a pretty common temp for tankless heaters.
If the water causes scale buildup it will happen regardless of the water heater type, a tank style will get buildup at the bottom, a plate style heat exchanger will also get buildup inside of it and require periodic flushing like a tankless.
Some tankless models also include a built in circulation pump to allow a circuit to be built in the plumbing to keep hot water very close to the fixtures. The programming of this varies, mine has the option of running every 15 minutes or a smart mode that learns our usage patterns and only has hot water ready when we typically need it.