I know its a little late for the original post. However, I have about 8000 miles using a GIVI Bag. I researched and tried several bags while having experience with others during my 15 years driving PC800s. I set a criteria first of what my needs were and I'll list them here:
1) Accessibility while inflight - I had to be able to reach inside it without looking and retrieve items (snacks, lip stuff for the wife.....)
2) Clear window for the map case - Though GPS is all the thing, what happens when it fails or is wrong? I want a hard map there to quickly and easily see my options.
3) Easy access when stopped. We keep our rain gear in there and I want to be able to stop quickly and apply without too much aggravation.
4) Quick and easy placement and removal. I want to be able to put it on the tank and then make removing it quick. After a long ride, I don't want to have to struggle with it. In the morning, I want to be able to just put it on and go. I am spoiled like that.
5) Durable and long lasting - self explanatory, these bags are expensive. I almost want it to outlast the bike.
6) Great storage options - I want it to be versatile in storage options. In other words if it is just me, then it fits so much, if it is both of us, then fit more. If I want to add while enroute, expandable.
7) Compartmentalized so that I can just deal with that part of the bag. This is different from access while in flight though may seem repetitive for #3.
It has been two years since I did my research plus the 8000 miles. I tried several as stated but can't remember what they were. Looking at my invoices, I tried a HH Mini Magnet Tankbag by Cortech. This unit was purchase from a motorcycle shop using their catalog. They had a model there but for a Universal fit. Price was a consideration but more usability was the biggest concern. I had a Cortech bag for my PC800. However, I let it go when I sold it as I wanted a Magnetic mount and the PC800 bag just didn't work.
I was able to get a fairly decent presentation when I looked online at GIVI. I have a long history with GIVI. I have had several of their top cases. One of which survived a 70 mph crash that totaled a PC800 beyond recognition. This now sits proudly on my ST1300. I went with the GIVI T437 Magnetic Tank Bag. After I returned the Cortech, I had my bike with me and the dealer allowed me to test fit the bags they had in stock. None of them conformed to the tank when stuffed full of paper. They sat ackward or would seat at all. A magnetic bag should be able to sit on a metal tank fairly secure all by itself. So far, the GIVI stood its ground.
The GIVI bag comes with the rubber-sided bottom, magnetic mount, a cinch strap that goes around the yoke, and four cinch straps that grip the bottom of the tank. I have only used the four hooks once. They do a great job in very windy conditions where there is a quartering or cross wind component. They apply quickly so if yo have to stop, down-time is minimal. The rest of the time , the magnet alone keeps the bag secured to the tank. However, I recommend that the the yoke strap be employed. This keeps the bad from getting lost in flight. I pack in the main compartment, one large and one extra large rain suit (jacket and pants), wipe towels (4), all needed maps plus two US fold out maps for that trip, any needed paperwork, snacks, 1 set each of day and night goggles, sunscreen, zip lock bags (4 qt & 4 gallon) and spare long sleeve shirt. In the right side compartment I keep: the four cinch straps, the rain cover (clear), spare batteries. In the left compartment, I keep lip balm, the MP3 device, several wet erase markers for marking the map in the clear case, incidentals.
The GIVI bag also comes with two shoulder straps that are hidden between the bag itself and the magnet mount. This allows the unit to be carried/worn like a back pack upon removal. It comes with a hefty handle to carry as a bag. I store the bag on the bike when not in use. I store it in clear zippered bag (the kind linens (bed sheets) come in). This keeps any dust off of it and serves a great second purpose. If by chance you pick up any metal fragments while preparing to mount this to the tank, the fragments drop harmlessly off when the unit is removed from the clear bag. Make double sure your mount side is clean and free of any debris. This will mar or worse scratch and gouge your tank.
This is my third season with this bag. I look forward to trips with the bag for several reasons. On the long haul, I can lean on it without taking a nap. It provide a nice cushion in front. This really helps to prevent those air-blasts that come up from below. The bike is easy to maneuver when mounted fully loaded. It also allows easy access to the tank for fuel stops. Notes can easily be written on the clear map case (which is removable) in dry or wet erase (wet won;t come off if you swipe it with an arm unless it is sweaty). One can very easily take quick looks at the map to verify position while in flight.
GIVI won my money several times with their top cases. However, their tank bags rule. They are sturdy, well built and can handle the long haul. My bag looks like I just unpacked it from the box and it has seen all weather conditions in 8000 miles of use in two seasons (1 1/2 really). The bag also has reflective markers sewn into the bag for extra viability. Should get a new or different bike and the bag goes with my old bike, I will definitely order another GIVI.