We booked 2 excursions with them. Paid the full amount for both. One tour got confirmed right away, the other was kept pending.
About two weeks out I checked with them on the status of the pending tour, and got a reply next day, they still needed 4 more participants. I waited another week and let them know by email we did not want to wait any longer and risk being without a tour. They accepted our cancellation and immediately made the refund to my credit card.
Then 3 days before arrival in Reykjavik things got confusing.
Got an email our tour would be changed. However the tour and date mentioned were not what I had booked. So mailed them about it. They recognised the email was a mistake, but at the same time told me our tour was also not going to take place.
remember; this was a “Confirmed “ excursion.
They did offer a very similar and longer tour as alternative at no extra cost. For me this would come too close to back on board time, so refused and cancelled. Luckily the cruise line still had space on their Golden circle tour so we took that in stead.
Again the refund was processed swiftly.
So I would say from my experience they are definitely trustworthy, but reliability could be better.