Onkyo makes one of the best pre-packages HTiB systems on the market period. People can certainly dump on HTiB systems, and for good reason, but to devalue the quality which Onkyo delivers over say... Samsung, or Sony with their Bosesque proprietary 2.38 ohm package systems is a shame.
At a MSRP of $600 the Onkyo HT-S5600 is a really good value, period.
Let's look at it:
Onkyo USA | HT-S5600
7.1 audio with TrueHD/DTS MA decoding on 4 HDMI inputs. No upconversion, but component and plenty of composite if needed. Zone 2 (WTF?) and 5-way binding posts with the use of traditional speakers.
The speakers are an obvious weak point, but the use of a 10" subwoofer in an apartment is likely overkill by itself. Wood cabinet, though I'm sure it's cheap stuff, but still, not plastic junk like you see from others, especially at that price point.
Now, getting serious on things - jump on whatever deal it is you've found. Heck, if they have several, come back and share the link! This is a real find.
Most of all: RUN SPEAKER WIRE!
Wireless is a lousy way to do things. It's silly really. Get some low profile speaker wire and run it around the edge of your carpet in the apartment and you will be good to go. Remember, wireless speakers still need amplifiers, so they need to be plugged in and really aren't wireless at all. So, acoustically, the best thing to do is run your wires. It may take a few hours... Heck, it may take even longer. But, if you thing that $250 is a fair bit of cash, then why not spend a few hours doing some research on the best way to run wires, the best wires to use, and then do a great job running wires for $50 and maintaining the highest level of audio quality you can get from it.
Down the line, with upgraded speakers, the Onkyo receiver likely will continue to perform very well and gives you a great jumping off point. I know I got my first (clueless) system as a Kenwood HTiB from Sam's Club. The speakers were wood, and they were weak, but I upgraded to Def Tech speakers in a couple of years when I could afford it and the jump in quality was astounding. I have no regrets with my original purchase, and with a deal like you are getting, you should just buy, and not look back. Especially considering that you are in an apartment and not in a single family home. Shared walls means that you don't need the power of a better system and you shouldn't be spending the money to really treat the room like you should in a dedicated environment that you own.
Enjoy!