I'm in the market for a PM, so I've done quite a lot of research on this thing lately. It isn't available yet - though the website says it starts shipping "in February" - and my emails to the company haven't been replied. Most people seem to think, with all the variables involved in their science, that at best this is a "guesstimeter". Even if the science is sound and you DO get accurate power feedback comparable to other PMs out there, there are a few things about it that just seem too impractical for me to feel like it's a viable solution. You need to weigh yourself and your bike - including bottles - before you hit the road. What happens as you empty bottles on your ride, losing as much as 12-15 pounds??? Well, then I guess your measurements will start to falter. It can also only give you consistent measurements in one position - so if you leave aero, problems are presented. Those are two big ones for me. I guess its viability as a useful power measuring device will be known soon enough (once/if it's ever released...), but these other factors are deal breakers for me. Which is too bad because the price is right. I'll probably go to a Polar instead, and hope the big guys see the value in coming down to the sub $500 mark sometime soon.

There's a lengthy thread about this at cruciblefitness.com right now. My confidence is further weakened in their not returning my emails, and in their not piping into some of the forums (there are lots of threads on this on tri and cycling sites) where questions about their methods and science are being asked (like how Ken shows up here once in awhile to talk about Evolution Running, or Rich Strauss, or the Lyte-N-Go guys, etc.) I'd like them to clear up misinformation, or provide information where it's needed, but they seem a little awol at the moment. We'll see, I guess!

I've heard back from John Hamen at iBike, and he's been very forthcoming and informative in his email exchanges with me. I have a few questions for him yet, but he directed me to this thread at Slowtwitch , where they're asking many of the same questions that I had, and he's responded in kind. I feel a lot less trepidatious about this product, and stand corrected in iBike's absence on forums. They assure us independent test results will be up soon on the site, and product will be available within the month.

iBike Pro Review.
I have an iBike and a Powertap and I have been comparing them side by side and here are the conclusions:

The iBike is NOT useful for training it is strictly a gadget and here is why:
The iBike is not at all accurate real time. MOST OF THE TIME the iBike is significantly (often 50-100 Watts) high or low. If you have ever (seriously) trained to power then you know that just a few watts (let's say 10% of your max hour of power; 25-50 Watts unless you are Lance Armstrong prior to 2006 (sorry Lance)) high or low makes a HUGE difference when you are trying to hold a set wattage for a while; and with this much error, you will have a horrible workout with the iBike. Sure, the marketing folks at iBike like to point to average watts and say that it is accurate but this is not relevant to real time training on the bike. The iBike is USELESS as a real time wattage training tool. There are also several other serious problems for example:
1) What about WINTER time ??? YOU CAN'T USE THE iBIKE INDOORS ! You will have to buy 2 power meters anyhow so what good is it ?
2) The iBike is completely inaccurate on the slightest rough road.
3) Turns. The iBike is flat out wrong when going through turns.
4) Drafting. Yes, the marketing team at iBike want you to think that it is more accurate when in bigger packs. BS ! I have tried it. It is WRONG WRONG WRONG in the draft.

So here is the conclusion, If:
1) You just like gadgets and don't care if they really work.
2) You never turn.
3) You never ride in the draft.
4) You don't mind a significantly wrong watts readout while you are training.
5) You are a sucker and believe all of the BS that iBike and those that stand to benefit from iBike sales tell you.
Then go buy an iBike -- There are plenty of them for sale on eBay from the people who have gotten suckered into buying one and can't get a refund.
Otherwise, if you are smart, go buy a PowerTap, Ergomo, SRM etc...

Have you ever seen Triathlete magazine give a BAD review of something?