Don't get me wrong. All three beacons I mentioned are great beacons. No matter which one you get you still need to practice with it. A lot. You should be able to locate and dig out a buried beacon in a pack in under four minutes, maybe five if you can bury it deeply. The only way you can pull that off is if you practice with it.
If you can find a buried beacon in four minutes and under, that gives you another 10 minutes or so to dig out your buried buddy. Recovering a person in under 15 minutes gives them the best chance for survival. Keep in mind for the average burial, you have to shovel out around 2 tons of snow. You're going to need some time to do that, and you're going to be very tired if it's just you. I also highly recommend practicing strategic shoveling so that you know the most efficient way to remove snow from your victim. Plus it will allow you to set up a triage area at the same time.