I just rode my Harley Heritage Softail Classic on a 400 mile business trip in order to test out the BR3400EX. I bought the bag in order to ensure that I have enough storage to pack everything I need for a multi-day business trip, and to provide a backrest for those long rides. This is a great bag. I did a lot of research before buying it, and was 50/50 on either it or the Kuryakyn 4141 Black GranTour Bag, and ultimately went with the Saddlemen because it was $30 cheaper at the time and looked like it had more room.The sissybar slipcover fits perfectly over my stock Heritage passenger backrest, and the bag comes with 2 quick-clip tie down cables to strap the bag to the chassis of your bike to ensure that it doesn't move around during rough riding conditions. There are 2 adjustable rods on the back of the bag to reduce the size of the backrest strap. The instructions say that the fully opened strap was designed to fit most Harley stock backrests, and I'd agree with that based on the perfect fit over mine.There is a padded laptop section with elastic velcro strap inside the main compartment. My 15" 2010 MacBook Pro is almost too big to fit in it. It's too wide to slide in sideways, and it sticks over the top edge about 3 inches, but the bag still closes. With all of the mesh pockets inside and the external zipper compartments on the side and top, I'm able to store all the computer gadgets I need for work. The main compartment is also large enough to pack 3-4 days worth of clothes in addition to my Shoei Neotec Helmet - Black - Large on top of all of that once I pull my laptop out.There are only a few things I don't like about the bag. Firstly, I tried both the sissybar strapdown installation and then the freestanding underseat mounting pad method, just to get a point of comparison for which way I prefer. I think the underseat mounting pad would scratch the fender paint, and even after securing the bag with all 4 quick clip tie downs, it just wobbled around on the passenger seat. There's NO WAY I'd feel safe using this bag without a sissybar, as I couldn't get it to lock down tight enough with the underseat mount straps - and it looked like the D-rings might actually rip the stitching in the bag I had them pulled so tight. Secondly, and more importantly to me, the bag comes with a velcro-backed pillow which attaches to the sissybar strap. Saddlemen's instructions say to either use the pillow for a passenger when the bag is installed on a luggage rack behind the sissybar, or for the rider when using the underseat mount. There is no out-of-the-box way to use the pillow with the bag mounted on the passenger seat via sissybar strap, because the velcro is behind the backrest facing the back fender. I want to lean back on the front of the bag while the back is secured around the sissybar.I personally got around this limitation by trimming the 2 black tie down straps' extra 12 inches of length off after sizing them to my bike and leaving a few inches of slack to get them attached. Then I sewed them to the back of the removable 'external sissybar strap protector', which was designed to keep the main sissybar strap hidden tightly behind it during underseat mounting, and also has velcro to attach the pillow on it. The top strap slides perfectly around the front pocket flap and the bottom strap loops around the two quick clip straps that lock the flap down to the bag. So now I have the bag securely mounted to the sissybar AND I can use the backrest on the front of the bag. Saddlemen should really modify the bag to facilitate this type of configuration from the factory. I've posted pics of the bag installed on my bike and of the modifications I made to use the backrest. I highly recommend the bag - it made a huge difference in reducing back strain and overall fatigue on my 400 mile ride, and I was able to pack everything I needed for a multi-day trip with room to spare.