I never drive a car without it. With old cars, this really came in handy. When my 325ix had problems with the alternator, it was there to help me out. When the Sears battery died in the 318i, it was there again to get me on my way. Die Hard batteries my a$$, only lasted 3 years, and get a pro-rated warranty and discount on a new one tho.
I used the Booster Pack to help a number of people stranded on the side of the road quiet a few times, just helped a guy in a Chrysler 300C in Calgary last weekend. The car stopped in the middle on the road on a very busy street, just had to drive pass him, back up, pop open the trunk, take it out, hook on the two terminal, start car, unhook, put back in trunk, all less than 5 minutes. Why such a long story, I strongly recommend people to get one, especially the ones came with a compressor and light, AC outlet. You could never know when you would need it, but growing in SaskatBush, it is one’s duty to help others when they need it.
Another thing I recommend is a simple charger, I use it condition the battery once a month, works very handy in winter. Every little thing in those cold days helps.