Location and Transportation
Avi's place is in a residential area near National University of Singapore. Once you get to the train, it's about a 15+ minute ride into the downtown areas, depending on where you're going.
Singapore's taxi service is really efficient and affordable. You can call for a taxi to come to the building entrance, and they will usually be there within five minutes. This is by far the most convenient means of transportation, since you can stay cool for the entire journey. I used Comfort Taxi, and their system remembered my location so that requesting a taxi only took a single keypress during the call.
The public transport system in Singapore is great. However, as someone who is not accustomed to equatorial climates, I found walking in the heat very uncomfortable, and even the 10 or so minute walk to the nearest station (Buona Vista) difficult. There are buses that make the trip to and from the (Dover) station quite a bit shorter. Avi may have other suggestions too.
Avi's place is very clean. He has refrigerator, microwave, and washer, but no dryer. There is a laundry service not too far, if you want it (ask Avi).
He doesn't use A/C in the apartment, but you can set your room's temperature individually. Ask for a tutorial for the A/C remote if you have trouble figuring out how to use it.
The wifi worked very well.
The private bathroom was comfortable and functional. The toilet was a bit temperamental, needing some serious coaxing at times. Tip: press down the handle really hard.
Avi's a vegetarian and asked that I not bring any meat products into the place, which was fine with me. There's a hawker food place open pretty late nearby.
Avi is a very nice guy, and was extremely helpful, giving me a ride to Holland Village at the beginning of my stay, very flexible about checkin and checkout times, and letting me keep a suitcase at his place while I went to Kuala Lumpur for a couple of days. He clearly was invested in my having a positive experience, and my sense was that his helpfulness was motivated by genuine goodwill. I feel like I made a new friend in Avi.
Mobile Phone SIM Card Availability
If you're like me and want to buy a SIM card when arriving, be warned -- the 7-11 and both Dover and Clementi stations did not carry them. Even the Holland Village 7-11 didn't have SIM cards, though I was told that they would be receiving them when their manager arrived later that morning.