If you go into the history you will find several topics on stabilization. I wrote a bit of a pros and cons of each system about 2 years ago. We went through the same process as you are going through and before we took a decision I contacted most of the producers, spoke with them, spoke with users and in the end I decided what system we would install.
My demands were simple, I wanted stabilization under all circumstances which means underway, at anchor and even in port (if necessary).
In addition I did not want it to use a lot of electricity, I needed to be able to run it off the batteries (and solar during the day) and I wanted a system that would not be overcomplicated. Overcomplicated normally means more options to break down while on the water and I don't want to be in a storm, finding out that the stabilization failed because one simple hose starts leaking etc.
A gyro, if heavy enough, can be a very efficient system, it can and will stabilized the boat. When it comes to gyros it is all about the 'self righting moment' which means the gyro wants to stay in the position it was placed in. That can either by via a lot of weight and a lower RPM or via less weight, but a much higher RPM.
And in order for that gyro to keep the boat stable it needs to be attached to the boat, which can mean you will have to reinforce the hull and make sure that gyro cannot break off its supports. Any roll movement the boat makes will result in a opposing force by the gyro (which wants to stay upright) and that force goes into the hull.
That said, a gyro becomes less effective when the speed of the boat increases, so gyros are indeed at their best in low speed boats like trawlers.
There are a few things to take into consideration when you want to use a gyro. If you live on your boat, like we do most of the year, and you spend a lot of time on anchor a gyro may not be for you.
First and foremost there is the spool up time of the gyro, which can vary between 30 - 45 min and if you need stabilization quick (due to a sudden storm) you can forget about it, that is not going to happen.
Second is that the gyro does require a lot of energy and that means the generator needs to run all the time and also needs to have a lot of overcapacity. That is going to put hours on the generator quite quickly, resulting in a requirement for maintenance and of course there is the fuel usage of the generator. My generator uses 3 ltr of diesel per hour when it runs at 100 %, so having the gyro on for 24 hrs would result in 72 ltrs of fuel each day and in one month that could be 2100 ltrs. With the fuel prices in Europe that was a bit over the top.
Of course you can switch off the stabilization, but was is the point of having stabilization and not using it because the fuel cost are too high ?
Also, if you have a small generator, e.g. like the one I have which is a 6.5 Kva Onan, it would mean that I would lose half the available power of that generator to the gyro. That would seriously impact the way I can use the boat. In fact, I would have to start switching off equipment in order to run the gyro.
There is one other important factor about the generator and that is that I won't run a generator while I am asleep. That is just too dangerous, so that is a no no for me, but it would also mean I would never have stabilization at night, which does not make sense at all.
Third, there was the need for maintenance of the gyro, which truly shocked me. Seakeeper told me that I would have to change the bearings every 5000 hours and that would require a complete tear down of the whole sea keeper by an authorized mechanic. In order to do that I would have to empty my salon, remove all the sound proofing material from the ceiling in the engine room, just so that they would be able to gain access to the engine room with a hoist. Since we spend most of the year on the water, also mostly on anchor, we would get to those 5000 hours basically every year. Doing that type of maintenance was a no go item for us.
Recently there was a topic here about a Quick MC30 gyro and that one does not seem to need this maintenance, which would be an absolute positive point.
In the end it meant a gyro was not for us. I can however understand that, if you only use the boat a few times during the month and only anchoring in very well protected bays (where you don't need the stabilization) then a gyro can be good for you. Also, if you sail in an area where there are a lot of logs and other debris in the water you are better off with a gyro and not with fins. Don't know how it is in the area where you are sailing, but that might be one of your considerations.
So we choose to go for electric fins. They run at 220 V, use minimal electricity, don't use up a lot of space in the boat and I can have them on 24 hrs a day. If there is no disturbance in the water they are at rest, but the moment we would get hit by a wave or wake they immediately get into action and keep the boat stable. In one year we have put almost 6000 hours on them, this winter will be the first maintenance. I will have an official rep do that maintenance, so I can see and record what needs to be done and what to pay attention to. After that I will do the maintenance myself every year, there is not a lot that can go wrong. If the electric motor functions the fins will function as well.