For many years I have owned both a Simrad
TP22 and Raymarine ST2000+, which I use on my approx 3.8 tons (loaded) semi-full keeler.
So I'm pretty well placed to compare them, and here's my 2 bob's worth:
* Functionally I found not a lot of difference between them in controlling the boat, although the ST2000+ stroke is noticeably quicker and it is much quieter.
* I have read lots of posts about failure of TPís and STís due to water entry, so some sort of cover is essential. I make a simple cover from clear plastic taped on and replace it each year or so. I also use electrician's tape around the body joint. Looks like poo but works well.
* A major defect of the ST2000+ is lack of protection against stalling at the end of its stroke (ie hard-over tiller), when the motor will keep grinding away. This can eventually cause a range of problems including motor burn-out, stripping of the drive belt, unscrewing and detachment of the push rod, and breakage of the bearing support mouldings. How do I know? Because I experienced all of them. My boat used to have significant weather helm
until I did some work on it, and sailing in brisk winds (nothing over 25 knots) would cause hard-over tiller for longish periods. So it's vital that you have good sail balance to avoid heavy weather helm
and hard-over tiller. By contrast, the TP22 has drive gear
rotation sensors which sense stalling at the end of stroke and quickly shut the motor off, hence it is immune to those problems. I eventually fitted limit switches inside my ST2000+ to solve the problem and it has now worked like a charm for over 3 years.
* Both benefit from tuning according to the boat and sea conditions. This can save an enormous amount of battery
power due to reduced stroking. Performing this tuning is much easier on the TP22, as it can be done on the run while it is operating in auto mode. But the ST2000+ must be switched off auto, which means sailing with your knees while trying to press the buttons. Itís not a frequent issue, but can almost impossible if you are solo in bumpy seas (which is of course just when the adjustments will be most beneficial).
* Both accept NMEA 0183
and hence can steer to a waypoint, and/or in wind
mode (if you have signal from a wind
instrument). Very simple 2-wire connection for both.
* Both are ridiculously overpriced considering their fragility, simplicity and manufacture en masse.
* When I bought my ST2000+, it had a global 2 year warranty (even if bought from overseas) plus an additional year if registered on Raymarine's website. The Simrad
2 year warranty was based on where it was bought hence no local warranty if bought overseas.
* The LCD display on the ST2000+ is nice to have but not really much use unless you don't have the data already displayed on a plotter
I'm on a budget
and not doing any serious ocean stuff so my TP and ST are good enough. But if I could, I'd upgrade to a Pelagic which are a much more serious and capable bit of kit. If you do go with a basic tiller pilot, you'd be well advised to take a spare, especially if you're sailing solo.
And of course there are wind vanes to consider............
Hope this is helpful,