I have booked Melrakki adventures with my sister following some friends' advice and we had the greatest adventure ever. Starting at 9:00am we were the first group (of 3!) on the glacier, so we had it for ourselves. The hike was fantastic, Katerina (our guide) gave us tips, stories, explanations and fun facts about this unique place. We could feel her passion for her work and her philosophy about being environment respectful and careful. I can only recommend them.
PS: on our way back form this tour, we have run into concurrent companies guiding no less than 15 people per group, making ourselves happier than ever to have benefited from this incredible experience as a small and fun group.