I will be maintaining three Volvos--an 850 in Norway and two V-70's stateside. I looked initially at the Equus 3100 and Auto X-Ray EZ. The Equus at $120 seemed like a nice buy because you could throw it in the glove box or haul it around in your luggage. But you couldn't upgrade the software (an important point??). The Auto X-Ray for $170 is upgradeable. But both seem to limit you in the amount of diagnostic information you can get and what can be presented on the LED screen. And then there's Alex Peper's software which many on the Brickboard recommend as the best. Just how much better is Peper's software, and does it justify the added hassle of lugging around a laptop (for the computer in Norway) and a long cord for the V-70's in the US? Will pulling the codes and finding out what they mean solve most of my problems associated with these three cars, or am I better off with Peper's software? I'm still confused about what all of these code readers will and will not do. I need some good advice. Dick