The Residence San Giusto is lovely. I can only imagine it's a failed condo project turned into short-tern hotel-style rentals. We stayed in two studio apartments (on two separate visits.). Each studio was twice the size of the typical European hotel room, with a huge bathroom (good shower, no tub) and a kitchenette (4 burner stove, no oven, no microwave: Italians want to cook pasta, not heat Lean Cuisines) and an adorable three-quarter size cherry red refrigerator with a usable freezer compartment. The units are smartly decorated and immaculate but may smell of smoke: this is not a non-smoking facility.
IMPORTANT: You check in at the HOTEL San Guisto which is kitty-corner across the street. Breakfast is available there as well, at a very reasonable price for about as good a buffet breakfast as you're likely to find in Italy--plenty of scrambled eggs as well as good breads and an assortment of meats, cheeses and fancy pastries.
ALSO IMPORTANT: We saw one room at the HOTEL San Giusto and didn't care for it at all, so be sure not to confuse the hotel with the Residence. The hotel rooms are small and old and musty,
The Residence San Giusto is a good 20 minute walk from the center of downtown (and it's uphill all the way coming back) and probably 30 minutes from the train station by foot. Local busses run frequently, however, if you're not a walker. At the Residence, you will find yourself in a busy middle-class neighborhood with quite a few retirees and lots of small traditional shops. We loved the neighborhood.
Finally, if you've never considered coming to Trieste you should start thinking about it now. Trieste makes a terrific basecamp for some fabulous day trips. In the summer, you can travel by inexpensive ferry in the calm and beautiful Bay of Trieste. You'll want to visit Miramare, Duino, Aquilea and Grado at a minimum (all mostly by ferry) and you'll want to take the tram to Opicina and take the lovely walk along the ridgetop. This weekend we'll be taking a longer ferry to Pula, in Croatia, and the following week we're going to Koper in Slovenia. The Dolomites and Venice are close too, as is lovely Ljubljana. And Trieste itself is quite grand.