We had a wonderful 5 nights at Anton's home and in Valletta. As others have mentioned the location is ideal and cleanliness is top class.
We'd also agree that the smaller point of layout of the second *bedroom* potentially posing some awkwardness if guests are not all on good personal terms and that the second bed would benefit from a thicker mattress, to better cushion its frame.
The apartment was peaceful, well equipped and decorated with taste and character. Communication with Anton and Maria was excellent - both going above and beyond. There were lots of information made available on what to do in Malta. WiFi was excellent.
The only other thing which we would have changed would have been having the washing machine upgraded to a combination washer / dryer. We got really soaked from heavy persistent rain on just one day there and using one of the AC units on its hottest setting we still struggled to dry some clothing items, which we needed to re-use. A more trivial matter but something possibly worth considering for those rarer times when drying outside in the sun isn't an option?
In summary, we'd highly recommend Anton's place and Valletta and we'd love to return.