Nothing wrong with a tiller pilot for your intended use. I just replaced my (old and failed) ST1000 with and ST1000+.
had one on the shelf and matched the best internet price
I found so I was very happy.
I was very happy with the ST1000 and am very happy with the new one which has a little more power. The installation
instructions are fine and they have lot's of extensions and adapters to match a wide variety of tiller and cockpit
The unit interfaces with nav and wind
systems if you want it to. I had the old one coupled to a handheld GPS
for a while but that's really only useful while motoring a course. I don't have wind
instruments so haven't used that feature.
I generally use it the way you intend. Hold a course while I hoist sails
. It is particularly useful when flying the spinnaker
The autotacking feature isn't that great and I will sometimes get caught in irons letting Otto tack the boat in light conditions. I could shorten the coupling to the tiller and get a greater rudder
angle but I find if I get right up close hauled with decent boat speed it works OK.
Don't have any experience with Simrad