Holy Bonjovi, it's our life and we need to explain something very important, P-type cells (the standard for just about every panel) vs N-type ( the top of the line, tech-guru endorsed ones). Well, to cut all the crap, and explain in terms that normal people can actually understand, the difference is price and performance!
P-type cells essentially have the power travel from the top down through the cell and are cheaper to produce. They work fine, and just about every system we have sold has P-type in them. However, we have just started selling the N-type models, whose power travels totally the opposite way, and woo boy, there is a difference once installed.
Firstly, N-type cells allow a much more efficient output, so you can do say 440 watts instead of 370 watts from the same size panel. This has a variety of benefits, including less cabling loss as fewer panels are required. And, from what we're observing, better absorption on low light days.
P-type cells still totally dominate the market and will continue to as most consumers simply don't have the brainpower to spend a little more upfront and get the extra benefits back a few months later (sorry for being harsh, but we're cutting all the crap here). Unfortunately, Australian solar consumers are known around the world as the idiots who buy systems on price (the fact that most of our industry operates out of India and China is partly to blame, henceforth why so many companies tell you they don't need to do a site inspection, they can't ). This means that just about every quote you will receive has the cheaper technology...
So, which one do you need? Well, as a rough guide, there are exceptions if you're going to be in the house for more than 6 months, spend the money upfront and reap the rewards later. If the system is to help the sale of a property, or you're a builder and won't have to worry about the performance, then P-type cells all the way!
Hopefully, this helps explain a very important, yet very rarely understood, part of our industry. To give you an idea, no installers that we've spoken to had even heard of the cell differences, and it doesn't factor in when actually doing an install. Hence some of the confusion around it.