I use them all the time. They're fine as far as how long they hold a charge. They are also convenient in that when they do start getting low - it's only 15 minutes to charge them fully. I'm sure it costs me less in the long run, but eventually the rechargables do stop taking charge and need to be recycled. While I've never accurately measured the lifetime of those batteries, I'm sure it's at least 3 years. But that may depend on the brand you choose.