I agree with the poster who mentioned the problem with Triumphs. No matter what the Mac site tells you, these are not very popular because of the shallow seat. Get the Quest if that is the type of stroller you are looking for.
The Volo is extremely lightweight. It does not recline. The 05 models come with a sun canopy, earlier models do not. Many people love this stroller that do not have children that nap or need the recline.
The Triumph is a step up, but as I said, the seats are an issue.
The Quest is a bit heavier than the Volo but reclines and comes with some more options.
The difference between the Techno and the Quest, besides for the price!, is that the Techno has a full recline therefore being suitable for an infant. If you are looking for a stroller for a toddler, the Quest would be enough. If you are planning to use it for an infant, then you would get the Techno.
For those of you in the NYC area, Buy Buy Baby is selling Quests for $129 right now (usually sell for closer to $199). The Volo is $69 I think. Target is also now selling Maclarens as of this week.
You may also want to consider the Inglesina Swift. It's similiar to the Quest. Also the Silver Cross Mini. The Silver Cross Micro is more like the Volo in that it doesn't recline.
For babies, you may also want to consider the Peg Perego P3 or the Inglesina Zippy. Both are umbrella strollers like the Mac Techno, but they have napper bars. I think they are around the same weight as a Techno.
ETA: Sorry for posting some of the same info as above, I didn't see that this thread had a page 2!!!! I see some of my friends at the StrollerSwap on YahooGroups are here. It's a great source for stroller information but be prepared to get obsessed. Sometimes the less you know the better!