I had no idea what to expect, but was pleasantly surprised. L'hotel is located right next to the Chateau and an easy walk to the centre. It's around 2 mins walk to the Duchesse tram stop. Tram tickets are super cheap - a couple of euros for 60 minutes ride. I walked to Les Machines de l'Ile in about 20 minutes or so.
The room was very small but had a nice view across the Nantes rooftops. It was absolutely fine for one person, and would be for two people who are very cosy. With two, there would be very little space for luggage. There is no separate ensuite - that is, the bath/shower/sink was right next to the bed, just an archway. You could totally see into the shower from almost any angle in the room! So I would not recommend this room for sharing with anyone other than a romantic partner :) That said, the bed was very comfortable, there was a small desk, the wifi was perfectly good, and there was a nice view. I felt overall it was excellent value.
Breakfast was very pleasant - 12 euros per person. A small selection of cereals, coffee, orange juice, yoghurt, fruit salad, fresh fruit, pastries and bread. Scrambled eggs and tiny chipolatas were also available. It's a very small area so there's no 'buffet', but nonetheless I found it cosy and everyone was very friendly.
The staff were great - welcoming and friendly at all hours. Would definitely stay here again, hopefully I'll be back next year!