Got a pair of these a week ago from Sam's club, they're pretty good. From what I know the headphones themselves are identical to the QC45, they actually show up as QC45 in the app, so these are likely the same headphones just sold at a markdown through Costco and Sam's club. From what I can tell the only difference between these and the qc45's is the case, the SE's come with a soft case instead of a hard one. A hard case can be had for like 20 on ebay or ali express if you want that. So far the soft case has protected them fine in my backpack, which can get thrown around quite a bit. Someone mentioned it doesn't have passive noise cancellation, I assume what they mean is it is impossible to turn anc off without activating ambient mode. In other words, you can only have anc on, or you can have ambient noise pumped in. It's unfortunate, you really should have a third mode where you can just have nothing turned on but I haven't found it to be too annoying. Whenever I want anc turned off I generally want to hear my surroundings anyway. As an additional note, this is also true of the QC45's. Overall I have no complaints, at 200$ I think this is a great deal given the 45's normally go for 350 or so, and these are (From what I understand) literally just repackaged QC45's. More on reddit.com

I have both the QC45 and XM5 and both have their strengths and weaknesses. ANC - Both are extremely close. I've used the QC45s for 2 years on the opposite wall of a loud roommate and it reduced his screams to a muffled noise. Obviously, ANC isn't going to magically block noise 100% but the Bose were able to significantly reduce the level of noise of my surroundings. Sony's, in some areas, were slightly better but due to the ear cups (I'll come back to this), they didn't seal out as much noise as I needed. I would say QC45 wins, but by a slim margin. Adjustable Sound Quality - Sony wins this area, with and without adjusting EQ. Bass is stronger, mids are warm, and highs are sharp. Out of the box, the QC45s really don't hold its own when it comes to sound quality; everything feels slightly weak. Once you start messing with the EQ settings does it drastically become better (you have to really set the bass and treble up a few levels to make it start sounding decent).The Sony's app is straightforward, intuitive, and gives you plenty of ways to customize not only EQ settings, but for the touch controls as well. The Bose app is one of the most infuriating apps I've ever used. It constantly buffers whenever I try checking the battery percentage and, specifically for the QC45, does not have nearly the amount of customization as Sony.I think someone else mentioned this but for mic quality, the QC45s are just bad, period. My friend always jokes if Im in a box when I call him. Sony's is much much better. Comfort - I've worn the QC45s for 7+ hours straight repeatedly over the course of 2 years bc of studying. They are supremely comfortable. The only times I've needed to take them off was to let my ears breath a little due to my ears getting warm/sweaty easily. The earcups have plenty of padding as well as the headband for your head. Plus, the earcups are deep so there I've never run into the problem of the inner earcup fabric grazing my ears. I also wear glasses, if that helps. The clamping strength isn't too much but sufficient enough that they are able to help the earcups produce a strong seal over my ears, and therefore improve the listening experience. The XM5s are slightly less comfortable imo. The earcups are shallower, so I have run into the problem of the inner fabric rubbing against my ears. The headband is also narrower than the QC45s so while I personally haven't felt pain on the top of my head, my friend did when he tried them. The clamping strength is slightly weaker as well; while the QC45 clamps evenly, the XM5s clamp stronger on the lower portion of the earcups. However, the XM5s are lighter and therefore help them become less fatiguing. Despite the negatives, I am able to wear these for a while too, but not as long as the QC45s. Overall, both are excellent headphones that I use almost equally daily. In your specific case as a classical musician, I would highly suggest the XM5s due to the customizability of the EQ and just overall better sound quality out of the box. However, if you prioritize comfort, the QC45s win hands down (its in the name after all). Hope this helps. More on reddit.com

Was initially looking at the Quietcomfort 35 series, 45 series is 4 years ewer so supposedly has better noise cancelling and better battery life but looks like the 35 but with improved internals. Went with the 45 because I could not easily get the cheaper 35's before tomorrow as they were out of... More on bobistheoilguy.com

I partly agree and partly disagree, and I think a lot of it is due to me not being as against Bose out of the gate. My main pair are the HD 600's which aren't an overly "energetic" pair to begin with. Going to the QC45's, for me, isn't bad. As you said, they have nice bass extension, and I find they have quite an amount of treble too (compared to my 600's). They're a strong V shape, for me. Then I agree they have no sort of detail retrieval or soundstage. While the sound isn't the best compared to audiophile pairs, I think it's good for listening to modern rap and pop music, similar to how I find the DT 880's are great for old rock music but a bit iffy elsewhere. I think they certainly have a place for music listening, if they don't perform as technically good. I also find them outright better sounding than the 700's and QC35ii's. Those have no treble, recessed vocals, and a droning bass, which is a lot more bland for me. I think you're being harsh on the earpads. They're better than just "okay"; easily more soft and plush than the 770/880/990, the HD 600's, and others. They're very nice earpads. The dongle is probably your Bluetooth problrm. I don't think you're going to have a better experience with any Bluetooth headphones while using them with that dongle. If the noise is an issue, I'd recommend looking into the 700's. They don't have a noticeable background noise like the QC45's and XM4's do More on reddit.com