I have had a generation III iPro for about two weeks now, so I will give you my take on it so far. I do not really do any racing, so I was looking at it more as a ride analysis tool than anything else, so I really like some of the features like wind speed, gradient, etc. I do the occasional time trial and triathlon, but that's pretty much it. I have put together some power based training to improve my performance, but that wasn't the main reason I bought it. I decided on the iPro largely because I wanted to try something a bit different, and even though it is a bit pricey, it is less expensive than some other options, and had some of the aforementioned features that I liked. I realize that it is not a power meter, but rather a complex computer that does a decent job at calculating power relatively accurately. Based on some comparisons I read, the Gen III is within a few percentage points of accuracy of some of the major power meters, which is perfectly fine for my needs.

All of this is largely dependent on a proper setup, which was not nearly as complicated as I thought it would be. You weigh everything, enter your height, do a tilt calibration, etc., etc. The key things that have to be done are the 2 mile out and back calibration ride and the coast downs. The initial setup asks what position you normally ride in to estimate the wind resistance, but if you do the coast downs, it overrides this and the computer figures out the actual numbers for your riding. When I did this, I did three or four, on flat ground, and tried to use pavement that was about the average of road condition that I ride on.

So far, I have done 7 rides with the iPro, and I have been pretty happy with it. It has given me pretty good information when I am riding, and great info afterward. The software is really great and fairly easy to use. It has a lot of neat features that I am still wrapping my head around, but it has exactly what I was looking for in that it allows me to easily analyze specific segments, like steady efforts of climbs. One thing that I have noticed that was supposedly a problem with a lot of the earlier issues was vibrations and wind.

I have not been able to see any really unusual spikes or weird readings that could be caused by wind, and two of the rides I have done have been very windy, with 20+ mph gusts, both head and cross wind. You can tell that the wattage goes up when you are hammering into a head wind, but it seems to compensate pretty well for brief gusts, and it hasn't been giving me any crazy or inconsistent readings in varying wind conditions.

I have had no problems with vibrations, and I have ridden over a few bad stretches with quite a few potholes, cracks, and broken up segments. I am not sure how that was messing with the earlier ones, maybe screwing with the tilt sensor? So far, it has not been an issue, even though I have hit quite a few jarring spots on the road. I have only had one weird spike out of all seven rides, and it showed up as a very brief (20-30 second) segment where I made 800 watts. I am pretty sure that never happened to say the least.

There are a couple of problems I have with the iPro. First is the issue of changing positions. While I certainly do spend most of my time in the hoods, I like to stand up from time to time. Based on the software, this shouldn't be an issue on major climbs since the resistance is coming from the slope and the rolling resistance. If you are a really strong rider, and you are going fast enough for wind to be a bigger issue, then this could present a problem on climbs. I am not that rider. However, this is a problem for hammering up shorter hills where you just stand up and mash. Again, for someone like me, the discrepancy isn't huge, and isn't that big of a deal, especially for what I am trying to accomplish. For a serious racer though, this could be an issue.

The other major problem is the downhill wattage calculation. After reading their website stuff again, I think I am more confused on how it calculates wattage going downhill. There are times when I am pedaling downhill and it is registering 0 watts, and other times when I am not and it gives me small trace numbers in the double digits. All in all, it's a little odd, and this is the only major issue that I did not think about before purchasing the unit.

One last thing, the customer support is awesome. I had a few issues with getting my iPro to connect to the computer, and their tech support were really pleasant to work with, incredibly patient, and most importantly, easy to get on the phone.

All in all, I am happy with my purchase. I also realize that this is basically an advanced cyclocomputer, and it isn't a real power meter. For me, that's fine. I can get a lot out of my ride data, the power readings are supposedly accurate enough that I can get some training value out of them, and it gives me a ton of other great information about my ride. However, I am not a serious racer. The few races I do are solo rides that are sustained efforts mostly in the same position. I don't really have any need to measure very short peak wattage for sprints, and don't need to measure my wattage in a group ride scenario. Both of these would present big problems for the iPro.