Heart Rate Monitor Really Worth It?

The heart rate strap will not bother you. I have found the Garmin 305 worth it. How I use it has changed, but it's that flexable. Not sure about the 310x because taking off a wetsuit with that divice might cause problems? I use the 305 for training, and only for bike during a race to keep check on my heart rate and cadance. (I have a tendency to over do it on the bike and have nothing for the end of the run.) Thinking of a powermeter, but that's serious cash.

x2

I went through LTHR and VO_max  testing to establish my baseline numbers (both running and riding) and then my coach used that data to design my training plan.  I also had the opportunity to attend a workshop with Joe Friel on HRM training when I was first getting started.  A HRM monitor can be a useful tool, but not necessarily the only thing you use.  There are times when I override my HRM with RPE, such as in the extreme heat we can get here in FL.

Mark 

I use the HRM biking to help me keep up my effort.  Other than that it is just neat to know information for me.  I learned the old fashioned way without any straps or wires attached to me or coming out of my head.  I don't use it on race day.

My zero 2.

CP2K

I didn't use a HRM for the first 30 years I was running...it was all on RPE, and I did pretty well with that. But a couple of years ago, after having been doing triathlon for about 3 years, I decided to go with HR training primarily because I was convinced I wasn't working hard enough. Anyway, hated it with a passion at first, eventually worked into it, and it has really worked for me in terms of becoming more efficient and faster at lower heart rates. I also believe it got me through IM training.

That being said, I don't use the HRM all the time during training (about 75-80%), and I never use it racing (I don't even start my watch when I race) because I tend to get too wrapped around the numbers and what they "should" be.

As for expense and which kind...I started with a very basic Polar that did nothing but HR. Then, I got tired of wearing that and a watch. So, I graduated to a Polar F6 (a little over $100). I had problems with the buttons...not sure if it's because I'm left handed and wear my watch on my right wrist, but I kept turning it off. So, I started looking at something different with a little more functionality. Like you, I didn't want to spend upwards of $200, plus I have really small wrists, so the laptop computer that is the Garmin Forerunner 305/205 et al. just won't work for me. However, Garmin also offers non-GPS HRMs in the Forerunner 50 and FR60, which are a more reasonable size for me. I have the Forerunner 50 with the foot pod and bike speed and cadence sensor. So, I get HR data as well as speed, distance, and cadence information. The foot pod is very accurate (I check it frequently). The Forerunner 50 is about $99 (without the bike speed and cadence sensor). The only drawback for me on the Forerunner 50 is it's memory is limited to 7 hours. So, I am going to give my Forerunner 50 to my hubby and get the new FR60, which provides a little more info on the screen (and my eyes are still good enough to see it) and has a 12-hour memory. It runs about $199.99.

The ability to upload data is useful for my coach, too, as it provides objective feedback with my own subjective commentary, so she has a pretty good idea of how things are actually going.

And, yeah, sometimes the HR strap bugs the hell out of me. But, usually, I don't notice it.