Recently got a Gears Canada Navigator Bag for my upcoming trip. Originally was going to buy the Wolfman Beta but recent purchases of chain, sprockets, windshield and helmet made me look for something more economical. The Gears bag in made in the same style with drop down pockets at side that hug the seat. It's 52 litres as it's quite large and has lots of D rings to stack tent, sleeping pad or other gear bags. I plan to stack an NRS Expedition dry bag on top with camping gear. The cost was 89.00 at RevZilla. I'll report on how it performs after trip next week.
If you get this bag one of the first things that needs upgrading is the bungee cord. The stock cord is very thin and one could stretch it a mile and still not be tight. Looks like about 1/8" and is totally worthless so throw it away. I found some 1/4" that I had left over after upgrading the bungee's on my kayak that seem to work really well. With the bungee's one can strap down rain gear, sleeping bags, etc. The pics show the smaller black and white smaller bungee next to the upgraded solid black one.
The front straps are attached to the passenger foot peg cage and is in contact with the exhaust. This bothers me some as I'm concerned about the exhaust heat melting the nylon straps. Not much else to attach to though. A large velcro strap runs under the seat and the rear is attached to the rear grab bar. Not sure I feel comfortable ditching the front 2 straps though. I'm willing to sacrifice the straps though and test on the upcoming trip to see how they hold up.
BTW, the pics installed on the bike is missing the bungee cord as I reinstalled new one later.