I stayed with my boyfriend for two nights, loved it.
Location: very easy to reach, and Glyn gave us detailed info + picked us up nearby. From the boat the bus stop to Valletta is about 5 min walk, and the bus takes about 15 minutes. You can also walk to Valletta (45 min) or take a ferry (the stop is within walking distance and the ride is about 10 minutes).
Bedding and rooms: three comfy bedrooms with sheets and towels. Plenty of little cupboards to store your things. A small sink in the main bedroom. Bring a mosquito spray, but Glyn also kindly provides a small electrical thing to keep them away. Two toilets + you can shower in the marina.
Kitchen: tiny but with everything you need. Dishes, cutlery, towel, hard plastic glasses, mugs and a few pots to cook. Oven (did not try) and fridge.
Mini living room: nice couch and table + TV with connection. Wifi worked great, too. You can also eat outside if the weather is nice (small table on deck).
Communication: Glyn was really really responsive and helpful. Also just really nice in general :)
Overall: of course this is a type of accommodation that is not for everyone, as space on a boat is limited and you might be gently rocking on the sea. Our experience, however, was great. My boyfriend had never slept on a boat before and he had no problem adapting. REALLY GREAT EXPERIENCE!