I would highly recommend Alexis's apartment. It's small but has everything you'd need for a stay in Paris. It's on a busy street but was amazingly quiet once inside (worth noting this is probably cos it's on the fifth floor and there's no lift - not a problem for us but not ideal if you're not a fan of stairs!)
The location is ideal for exploring on foot with tons of bars, restaurants and cafés on your doorstep. It's a short walk to the river and only a couple of minutes to the nearest metro station if you want to go further afield.
Alexis was the perfect host. He was always very speedy to respond and completely flexible around our arrival and departure times. He was friendly and helpful and happy to give us local tips. All in all I couldn't recommend Alexis and his flat more highly.