My biggest complaint with the Cortech bags is that the zippers suck. In fact, the zippers suck on ev

Yes, I searched the forums. And the Luggage review thread. The cortech bags make an appearance once or twice there (not the Givi's), and have good reviews. air travel to australia On motorcycle-superstore, both bags get good reviews.
The Givi's are $20 less, and well, they're Givi. But it seems like the Cortech's are certainly very popular. I like that they're expandable, so that gives me room to grow. For now it'd be street clothes shoes, possible grocery stops or errands. I commute to work daily and want to stop wearing a backpack. Some people say the Cortech rain covers can blow off?
Both companies make good bags. The Cortech bags are versatile, cleverly designed, and work fairly well. They have some nice features. The tail bag rain cover blew off twice; the second time I didn't bother to replace it. The saddlebag rain covers are a PITA and don't really work. (The tank bag rain cover works okay but it's solid fabric so if you put it on, it blocks the map holder.) I don't use rain covers any more, except air travel to australia for the tank bag. I always line my saddlebags and tail bag with plastic trash can liners before filling air travel to australia them, then just ride. I leave the rain covers home and don't worry about the weather.
My biggest complaint with the Cortech bags is that the zippers suck. In fact, the zippers suck on every Cortech / Tourmaster product that I have. They use very small-toothed, cheap, nylon zippers. The zipper on one saddlebag gave out after it went for a slide. I replaced that bag, but now the other side is getting finicky, and one of the pulls broke off. The zipper on my tank bag is double-ended (can open from either side), but now only works from one side --the other side splits open if you try to use it. On the one side that still works, air travel to australia the pull broke off. (The fly zipper on my Tourmaster pants broke, too. I had a tailor replace it. The zipper on the jacket of my TourMaster air travel to australia rain suit is really finicky, and is easily cross-threaded air travel to australia if I'm not very careful.)
The Givi bag seems better-made and more sturdy. The fabric is heavier-weight, air travel to australia and the zippers are more substantial. It also has some nice features, air travel to australia but it is not as cleverly designed as the Cortech. Examples: It has a clear rain cover, so you can put it on and still see your maps, but it takes up a lot of room in the bag when folded, and is prone to fogging in use. It has shoulder straps to wear it like a backpack, as does the Cortech. When not in use, the Cortech straps disappear inside a pocket hidden in the base of the bag; the Givi has a separate air travel to australia clip-on air travel to australia harness, which stows inside the bag and takes up a lot of room. I have looked at getting the matching Givi Voyager saddlebags, which, IMO, are nicer than the Cortech, but cannot justify air travel to australia the expense, since the Cortech bags are still very usable.
Based on my experience, I'd say your choices are Cortech for versatility, or Givi for quality. However, doesn't Givi make a set of expandable saddlebags? If you can find that, then I'd say, go with Givi.
Extensive post and comments, thank you very much. I've a pair of TM pants and know what you mean about their zippers sucking. How much rain have you ridden in? Another problem/thought is that I want to keep these on the bike as much as possible, which means in the parking lot at work. Will I need to worry about them becoming swampy after rains, even if I don't leave anything in there?
Soft luggage is not waterproof or even water-resistant. You can use spay-on waterproofing, air travel to australia but that will only work for a brief, light rain. There are too many zippers and openings to keep water out. However, the bags dry out fairly quickly when they are empty.
I do not keep the bags on my bike when not in use, but I think you can do it without too much trouble. I keep the straps on the bike at all times, clip the bags to the bike when I need them, and un-clip the bags from the bike and carry them in with me when I get to my destination.