Refractometer? Is it worth it?

I searched and really found nothing pertaining to how well these things work. I found a few threads about calibrating them, that's it. I am sick and tired of breaking hydrometers. Is this a viable replacement? After searching, it seems one would still need to have the hydrometer, to take certain readings.
So, for all of you that have one, is it worth it? Do you still need the hydrometer? Would you buy another one? How hard is it to calibrate? Is it very accurate?
Thanks for the opinions.

I rarely use my refractometer. They're good for measuring OG, but FG calculations can be off by more than 5 points depending on whose spreadsheet or correction formula you use.

I recently got one; it's nice being able to take a reading with a tiny sample.

That said, refractometers are designed to measure fairly pure fluids. At times I've gotten a gradient rather than a sharp line when trying to measure gravity. There are a few reasons for this, including suspended particulates, dissolved CO2, and complex sugars.

One of my favorite toys I have picked up. They are great for taking quick reads during the boil, something you can't do if you have to wait to cool a sample...for this alone it is worth the $50 to me. But, don't consider it a replacement for a hydrometer. Usually they are pretty good with a good calculator to adjust for FG, but it is nice to double check with a hydrometer.

I've done 3 all grain batches with my new one, and I love it on brew day, when you can just pop a couple drops of hot wort onto it to get pre-boil gravity and OG, rather than cooling larger samples to test with the hydrometer. I have a hydrometer as well, so I have compared samples and the refractometer hasn't needed any calibration to match up perfectly so far. There are $30 versions available on eBay regularly. I got mine through AHS when they were doing a $30 one-day sale on them.

Great tool. I find the FG readings to be withing .001 or .002 which is plenty good enough for me... to the point I have not used my hydrometer in a year or so.

It took me a long time to finally get a refractometer, but now that I own one I only regret not buying one sooner. All you really need is a refractometer and a precision hydrometer for final gravities (mine goes from 0.980 to 1.020). I still use a precision hydrometer for my OG, but that's mostly because I'm anal. The refractometer allows me to monitor my runnings while fly sparging which is very handy. And taking pre-boil and mid-boil gravity readings is nice when you want to nail a certain specific gravity. If you're an extract brewer, a refractometer is pretty much useless and you only really even need a hydrometer for final gravities. But for any serious AG brewer, the refractometer is a valuable tool. Also, precision hydrometers are so much nicer than the standard ones you get from you LHBS they are worth the extra money. Instead of eyeballing to the nearest couple of gravity points, you can easily distinguish within a half point. All these tools won't make you better beer, but they do help with repeatability and they make my brew day go smoother.

It's a toy that is useful but not really necessary.

Thanks for all of the replies so far, it seem that is is about half and half here. I might just hold off for a while, since I still need to keep my hydrometer around. That was my justification for purchasing one.

It can be a very useful tool if you are All Grain.