You'll be hard-pressed to find a more central place than Manuel's. At the end of the street is the taxi stand - really convenient to get to the airport, train station, bus station. There are many, many restaurants and cafe's around not to mention most of the sites are within a short walk.
The place is very comfortable, well-equipped, and and feels bright and airy. The building is secure and convenient with a lift. The place invites a lot of relaxation the way the city of Seville does. The living room wants you to be lazy with a nice balcony to have coffee and people watch. The bedroom is comfortable and you can block out the light and get a long sleep. The bathroom isn't tiny and the kitchen in well equipped. The washer takes long and doesn't wring out the water completely BUT do not fear, you have access to the top of the building where you can hang clothes that will dry in no time.
Manuel is a GREAT host. We experienced Seville just on his tips and recommendations alone and we had a blast! We need seats to a good Flamenco and he got it for us. We wanted great food - all his recommendations were home runs (visit Triana!). We notified him that we were travelling with a 1 year old (not asking for anything) and when we got there he had put up a baby cot and baby-related things. Manuel wants you to enjoy his city. I accidentally damaged his stovetop coffee maker (that I replaced) and he told me "don't worry about it if you can't find a replacement. i'll tell you how much it costs, and it's not much. Just enjoy Seville.". A super host if I ever met one!
Just some notes on the location: it is central and there will be people walking up and down the street at all times and you'll hear them. In my opinion a fair price to pay for the location and all the conveniences.
If you do book this place, listen to Manuel's tips. He offers tips on great experiences and won't send you to places that are bad value / overpriced / touristy.