If you had to choose, would you use a transistor based circuit or a MAX232 or similar IC?
Definitely a MAX232 for me.
The transistor trick frequently works. The MAX232 always works.
The transistor trick doesn't work if you happen to connect it to another device that's using the transistor trick.
The MAX232 always generates the correct voltages and levels. This is important when you are connecting a device that actually expects your device to adhere to the industry standard.
The MAX232 provides ESD protection - it is designed to interface electrically with the outside world. I have killed several 2n7000 transistors in systems that used the transistor trick, just because they aren't ESD protected and normal handling generated killing ESD.
FYI, I think the Maxim part number is now MAX232E. As others have stated, there are clones available from other vendors (TI, Sipex, etc), and there are many variations - e.g. MAX233, which is large, expensive, and does not require external capacitors; the MAX202; the MAX3232, which runs on voltages from 3V to 5V; the MAX237, which provides more I/O buffers (for a full hardware handshaking implementation) just to name a few I can think if off the top of my head.
Check the datasheet for your exact part (vendor and part number including any suffixes) as there are also variations in capacitor value requirements (the original MAX232 needed 10uF caps; newer variants can use caps as small as 0.1uF).
I have had several frustrating troubleshooting sessions involving devices using the transistor trick. My only problems with the MAX232 is making sure I get TX and RX connected to the right pins on the connector.
-j