There is no one size fits all solution here and it depends on your boat, your sailing grounds, your sailing style, and of course your budget
. There are clearly so many permutations it's hard to make a recommendation.... not to mention that not too many people have extensive experience with different pilots. But since you asked for opinions I'll offer my experience.
I installed an Alpha3000 on Shiva (36' OAL x 6' deep fin, x 16,000#) after I got her new and hand steered for a few years... perhaps 3 at most. I was new to sailing and the boat and felt I needed to be proficient at helming the boat. Then I decided that it was simply often boring and did not allow me to do much else on board and as I was almost single
handing all the time... SO was not much of a sailor... the AP became for me a necessity.
I selected a below decks pilot opting for the more robust alternative to the belt drive units available at the time. This was in the late 80s. I did not have GPS
at the time ... it was very new etc.. and Loran
C, if I recall
was not even outputing steering information/interfacing to an AP. It was not an option and so I got a stand alone pilot.
The Alpha came well recommended and the install was complex... the drive arm which is connected to the ruder post. This has to be very secure and with all sorts of angles and clearances and so forth it was challenging. The install of the compass
and the control head were pretty standing stuff.
What I liked about the Alpha system is that the AP is mechanically disengaged when hand steering. This means no drag on the helm
and hand steering is virtually the same as it is with no pilot installed. It is engaged and disengaged by using a teleflex cable.
The pilot is then switched on and will steer the boat to the compass
heading shown on the rotary dial. The heading selection is also intuitive using the large dial marked off with degree increments. A quarter turn clockwise and the pilot will steer the boat 90° to starboard... and so forth. There are also dials for yaw and how many corrections the AP will make responding to movements of the boat. Obviously more corrections uses more power and presumably steers a better course.
The pilot performed flawless for 20 years or so and then there was a compass failure 2 years ago. I replaced the part and had excellent customer support from Chris as Alpha. Then last year the drive arm went south and it seemed to cause problems in the control head from the feedback loop. I don't understand this. But I had to replace both the control head and the drive unit. Again excellent customer support and turn around.. Simple swap out re install... and I got upgraded software
inside the old case and a new and improved and quieter drive unit. The repair was expensive and amount to replacement aside from the teleflex cable and the wiring
harnesses. The AP did about 35,000 milies including about 20,000 offshore
before the major repair after 25 years. I would say this is excellent service
from the AP.
I prefer not having a GPS
interface and interpret the course made good and so forth using a plotter. I make the course changes or corrections and input them using the rotary dial. This keeps me more involved in the steering...even if it mean I only do the navigation
and not the helming. I strongly recommend against interfacing and AP with a GPS as it seems it can lead to laziness and collisions at sea.
I can't imagine cruising without an AP and the Alpha is on duty 98% of the time... and I hand steer only in harbors, anchorages
and some channels.
I recommend the Alpha 3000 for a boat and style which is similar to mine with similar cruising style. It will pay for itself over time.