The technology used by the heart rate monitors that you purchase is very comparable to what is used in the medical industry, so they are pretty accurate.
Polar has been on the market since the beginning of personal HRM's. When we went shopping for ours, I really didn't consider another manufacturer.
My Lady has an FS1 and I have an F6. FS1 is an "entry level" unit and as such doesn't have any features other than basic heart rate and zone. MyF6 is right at the top of your price range and if we had it to do over again I would convince my Lady to purchase it instead of the FS1 for several reasons.
1. The F6 comes with a T-31 Coded transmitter, which means like a wireless network the HRM transmits it's signals wirelessly, with a coded transmitter a locked connection between transmitter and the wrist unit is created. Great feature if you are going to using the unit in an area where other HRM's will be, because your unit is locked together, you won't receive crosstalk with other HRM's in the area(think gym). So if your usage will include gym usage, this feature is something that you would need to seriously look at having.
2. The F6 has much better data logging features. You would think that this isn't something that you need, but it's one of the handiest features on my HRM. It's nice being able to look back at an exercise session and see what your heart rate was for the session along with calories expended, amount of time in the "Zone". It gives you a very tangible way to see details of what your body was doing while you were busy concentrating on your work out. You can even down load the information to your PC if you are so inclined. That isn't available for Mac users, but the history is still in the HRM's memory for a while until it's over written with fresher data.
3. Set-up was easier on my F6, even with it's increase in features, I had less trouble understanding it's set-up procedures. It's much more user friendly and offers small improvements in operation. On the FS1 you are allowed 3 "Zones" for activity levels of monitoring your level of activity, low, average, and high. These zones set your alarms for your heart rate and give you your rate setting for the "area" where you receive the benefit of your heart. The F6 on the other hand also offers an additional "Zone" named "OwnZone" or something like that, by programing in your weight and age it computes everything for you and tailors the watch to you with more accuracy and a little more seem-less operation.
The F6 is just over the top price range you required, but to me it is worth the little extra you'll have to spend to get it. The T-31 Coded transmitter is $40 t0 $50 by itself and if you are going to be in a gym atmosphere or around another transmitting HRM, it's something that you will probably end up with anyway.
