Yes! I highly encourage my cliets to purchase a HRM that holds saves past workouts. If they are more data savvy, then I will go with the client and help them choose the right peice of equipment for them.
You have to understand, there are a few reasons why I do this with my client;
1- The client has a better understanding of rated percived exertion and their heart rate
2- The data gives feed back and allows the client and trainer to progress accordingly
3- Lasty, if your client can’t get to the gym, you can always give them other work that works with the HRM.
I’ve had a few clients who did use the fitbit and they loved it. It was more for them (not for me although I found them useful as well) and to help them track mostly their daily caloric expenditure. For me it was interesting to see how many calories actually they burnt on each workout….(fun stuff)