Ok. I have a history with SENSO so I might be a bit biased when writing this. I think this is the third headset I have from them, and the newest generation looks/sounds like it actually is different/better, than the prev. gen. (I've upgraded from the 250).Why did I upgrade? Well... It turns out, that if you drop these, then run over them with your car, it tends to... 'slightly' ruin the audio quality. Not a lot, but makes listening to Klingon opera painful... I mean more, than the usual 'OH lord, my ears are bleeding' painful...Down to specs:Same build quality (excellent). I like the earhooks, since I use them for running and SUP. They stay on.Connectivity seems a bit better, the Bluetooth connection is a bit stronger. At least for me, it starts to 'drop' a good 2 feet further away, than the previous one.Waterproof? Yes, Mostly :) I fell in the sea a couple of times with these on (riding my SUP), without any problems (pro tip: gently wipe them down with a moist -yeah, I said moist- fresh water towel after you dunk it in the sea).Also, after a long run, I usually just go and have a shower with these on, so... yeah. Waterproof enough.(I have 'Danger' for my middle name, right...)Also if you are planning to get them wet, use the silicone earbuds, not the memory foam one (for which KUDOS for SENSO again!). Though audio quality and passive noise cancellation is better with the foam (if you can hear that listening to bluetooth music he-he :) but getting the foam wet isn't the best of ideas. Fungi love it though...So, use the silicone buds if you 'get active'. They are comfy enough.Battery life:I've tested 6 hours so far and I'm certain it had at least 1 more hour in them (app showed 15% charge remaining).The USB 2.0 charger cover is better than on the prev. gen. feels less flimsy/harder to open.Mic:it works Ok. you hear the call really well, but sometimes especially if I'm in a noisy environment the mic is having trouble picking up my words. I'd say that 1 out of 10 calls I have to switch back to my phone and cover the mic. on the phone to block outside voice.Packaging is the same as the 250, and I think they include everything in the packet that you need. Also some gifts!- A shoutout for the magnetic cellphone holder, however, SENSO if you can, please make the 'stick it on the back of your cellphone credit card holder' RFID blocking and I'll be happy to use it! the quality and make is nice, but... you need RFID blocking.-Would I buy it again? Well, I already did, so there is your answer.Would I tell my friends to go and buy it? No. it might push the price up and I'm selfish that way :) but yeah, I would advise them to get these.I only tested it on Android and my universal bluetooth connector and a Toyota, and connectivity worked kickass on them.