Pros: Nifty idea!
Cons: A lot of issues
I purchased this unit in January of 2012. I have had this unit installed on my 27' sloop for approximately 6 months, and the following has been my experience, up until now.
RayMarine's advertising suggests that this is an easy install. In some few cases, I imagine that this may be true. Keep in mind that each installation is custom, depending on your particular boat, and some installations have the potential to be quite complex and frustrating (see YouTube for some examples).
After you go through the trouble (and expense!) of a proper installation, you still need to work out the unit's current draw requirements over time. RayMarine has been extremely careful NOT to release 'typical' current draw scenarios, or even a simple maximum load / maximum continuous current draw number that could be used to give some sort of baseline idea of what to expect. This is understandable, they want to sell units and not scare away potential customers! I found, after long testing in moderate sea conditions that you can expect this unit to draw in the 3 amp-hour range. I've also seen approximately this number, from other users. This means that in a simple 10 hour voyage-period you could potentially expect a 30 amp-hour battery debit. Using this unit for 24 hours in moderate conditions could set you back as much as 75 amp-hours, depending on your vessel's performance.
On my unit, I've had an endless problem with an annoying, unstable compass heading reading. Tech support has been somewhat helpful, but has not been successful in resolving the problem, so far.
Another problem I have noticed is that the unit has trouble staying to a GPS route/track. I've got a Garmin chartplotter that communicates via NMEA to the autopilot (AP). While the AP will generally hold a somewhat decent parallel course, there is usually a substantial cross track error, making this feature untrustworthy in tighter quarters.
The autotack feature is pretty nifty, when it works. In the newer versions of the firmware, they no longer give you the option to select reciprocal tack angles, so sometimes the tack will be unsuccessful, particularly ugly when you're single-handing in moderate to heavier conditions, when you were expecting this feature to function properly.
The 'wind vane' function is a nice idea, but don't expect it to be as reliable as a real wind vane. I have a Raymarine apparent wind indicator set-up that communicates directly with the AP via SeaTalk. I have noticed that steering the boat in 'wind van' mode can be dicey, at times, depending on conditions. I have often switched back to 'auto' mode after experiencing unstable performance in 'wind vane' mode, and I am careful about my expectations for this feature.
Raymarine customer service is pretty good, but don't be surprised when they don't provide you with certain, otherwise obvious, answers. For example, don't ask them how you can purchase the one working part most prone to failure, as a stand alone. The tiller drive is not a stand alone item in their marketing minds, and they want you to purchase the core pack as a safeguard against tiller drive failure. Also, NEVER expect that they will help you out with current draw figures for the unit, other than draw during idle.
Knowing what I know today, about this unit, I don't think I would have made this equipment choice. There are plenty of other self-steer options out there, and the prudent skipper should take the time to explore these.