There is a lot of good information here. The BCA beacons (DTS and Tracker 2) are a good compromise between price and performance. The biggest issue with the BCA beacons, as has been stated, is that you can't "mark" signals. In a multiple bury situation marking allows you to disregard signals that have already been located, but you haven't turned off. For example, say you have three people buried in fairly close proximity. You locate the first one and a team starts to dig them out, and you keep searching. With marking technology you can tell the receiving beacon to disregard the signal of the known location, and focus on the next signals. Without it, you keep receiving all the active signals, which can cause confusion and slow down a rescue.
With a non-marking beacon you use special search techniques to help with the competing signals, such as micro strip, expanding circle or three circle searching. However, these techniques are a little more advanced and MUST be practiced and understood to be effective. More info here
http://beaconreviews.com/transceivers/MultipleBurials.asp and here:
http://www.backcountryaccess.com/index.php?id=163
If you are committed to practicing a lot and really knowing how to deal with multiple burial situations the Tracker 2 is a good beacon. It is fast, as it doesn't need to worry about marking, and has good range. If you want a beacon with marking technology, and a little more range, the Ortovox S1, Mammut Pulse and Pieps DSP are good beacons. In a recent independent review I believe they were ranked in that order, with the Tracker 2 in fourth place.
The biggest thing is to GET A BEACON and become intimately familiar with it. Any modern/functioning beacon is better than nothing. However, if you don't spend the time to get to know them and practice, they aren't much better.