Power meter cranks

My girlfriend has a SRM and I use a Quarq, so I have seen her use her's a little bit, and I have been using mine a good bit for almost a year.

I like my Quarq. Wireless, easy to change the battery, consistent results, easy to use, uses any third-party ANT+ display, and (like you said) much less than the SRM.

SRM is compatible with ANT+ devices, but they claim their device records significantly more data than any other device. The SRM has to be sent to a manufacturer's representative to get the battery changed (when my GF talked about it, she said there is only one place in the U.S. Oddly, in her mind, that made it a better unit. It's "exclusive" or something. I'd rather have "easier to deal with"). She claims that it has to be sent to Germany for service, but I'd like to think there's someone here in the U.S. who can work on SRM products by now.

As far as performance, I can't make a personal comparison, but I've read a couple of online reviews that said they're just about identical. There might be some way in which one is better than the other, but the user would have to be an ubergeek (I'm just a geek, no "uber" prefix) to take advantage of the difference.

Everyone has their own preferences for many reasons. Often I go with German-made stuff because I trust Germans to over-engineer everything from heck to breakfast and I love that. In this case I have to go with Quarq. Less expensive, you can change your own battery, easier to get it worked on, and it serves every purpose I can think of outside of cooking my pancakes.

I hope my rambling helps.

I'm still waiting on Garmin's Vector unit but likely will buy a Quarq soon, if Garmin doesn't figure out the Vector.  

The text below is an updated version of a year-old post of mine regarding power meters.

I've researched power meters like crazy and here are my opinions for all power meters:

The weird ones - no way.  Why bother with units that calculate your power rather than measure it with strain gauges?  There will be people who swear by them, just like those people who say Saabs were the best cars every built.  And hey my last car was a Saab.

SRM - no way, never again. I owned one for several years, happy to buy it, happier to sell it.  It was too much hassle to have that battery changed, once a year in the crank and once in four years in the SRM specific head unit.  This is battery replacement:

• print out order form from SRM website, name address, credit card #
• remove the crank, box it (keeping your box from the last replacement is best)
• take it to your FedEx center, ship it for $30 (or $60 insured) to Colorado
• pay $60 to SRM to replace the battery in the crank, slightly more for the head unit (IIRC)
• they mail it back to you, so you don't have your bike for 6 to 10 days or so
• install the crank

I just won't do all this again.  Quarq is just as accurate, and SRM has no justification for their higher price. SRM is in Dreamland if they think they keep on selling technology with only incremental improvements at sky high prices.

PowerTap - good choice if you don't already have wheels, or if you want it only in race wheels, or have one bike.  If you can have your wheel relaced to fit a PT hub, great.

Quarq - I may buy one of these yet.  I would like to stay Dura Ace, but oh well Quarq can't build due to the design.  Several of the cranks are same level of quality as Dura Ace, so no matter.  And now that SRAM owns Quarq I don't worry about being abandoned.

Garmin - well now this is the outlier.  As per Garmin's usual marketing strategy, they announce six months before availability and throw FUD into the minds of people like me.  On paper, they sounds great.  Multi-bike / multi-wheel easier than crank systems and the advantage of separating power from left and right feet.  The disadvantage of making me switch pedal systems, but similar enough to the one I use.  Also they're not here yet and may not live up to their marketing.  

And now it's been more than a year and they are still not on the market. But Garmin so far has a good reputation of delivering what they say they're going to deliver even if it is a bit late.

All said and done though, I'm waiting for Garmin's system.  I'm in no rush to have a power meter again on my bike, so I can wait a few more months.  But at some point I'll give up and buy the Quarq.