Almost 2 months later....
I've been using a Sports Instruments HR 90 for about 2 weeks, it's been working well with no problems. So far, it's been accurate...it doesn't do anything weird or unusual. With only two buttons that scroll through different modes and minimal features, it's easy to use.
It's a very basic HR monitor, you can set high and low targets and the screen will flash, not beep, when you're above or below. At the end of the ride it can show you how much time you spent above, below and in the set zone.