Owned a i5/256gb SP4 the day it came out, it replaced a SP3. Upgraded to a i7/512gb but then felt as if I paid too much for the functionality and the battery life was really insulting. The Lenovo Miix 700 is the tablet most close in appearance and functionality to the SP4 and I thought others might have the same quandary in choosing between the 2. Overall appearance I'd say the Miix wins hands down. It's black, metallic and very solid and high quality feeling. The black paint is of a very high quality and really looks nice in person. The watch band hinges are georguous and really give it some bling. Even the Lenovo logo is kind of a muted dark chrome, which looks very classy instead of how gaudy bright chrome looks. The front of the devices goes to the SP4, smaller bezel, larger screen, higher resolution, no logo to mar the front. They are both extremely close in thickness. Even though in my pics the SP4 looks thicker, the Miix is actually slightly thicker, slightly wider, but a good amount taller. The keyboards seem to be virtually the same thickness, but the miix keyboards is taller. The keyboard on the Miix is junk. Functionally the keys move well, have about the same travel as the SP4 kb and seemed accurate, bonus they are much quieter then the SP4 keyboard. The miix keyboard borders on awful looking, the keyboard side isn't bad, very understated as befits a business machine but I wasn't too keen on the rubberized surface, it just felt cheap. The back part is just a very cheap feeling piece of faux pleather plastic stretched around it and glued at the seams, the seams seem cheap as well IMO. It doesn't look like it will have longevity, but that's not based on anything other than aesthetics and it may very well wear and tear a long time. I had some issues right off the bat with the Miix 700 keyboard, I had a lot of ghost swipes on the trackpad where the faintest of swipes while going to another key would cause havoc with the UI. The Miix keyboard also would think it was disconnected when I folded it backwards and sometimes when just typing on it, I'd hear the MS chime for disconnected hardware and would make this happen at will. I also had a lot of odd UI issues, desktop focus being taken by something invisible, windows switching, I have no idea where this was from. Software: Both of course are win10 pro, kudos to Lenovo for providing the pro version at such a price point. Lenovo does have shovelware installed though of questionable usefulness, although that depends on your needs. Lenovo did go to the trouble of allocating disc space to store drivers out of the box. The SP4 has issues with waking, staying asleep, waking up with a black screen, graphics driver crashes, etc. The Miix ran very smoothly overall other than the UI changes, it was awesome to not have a fan and the tablet did not get very warm unless run hard. Power seemed abundant, I've ran Fallout 4 on my i7 SP4 and I get 20-25 fps with everything turned down at 720p. It only ran a few fps slower on the Miix. I know the SP4 throttles voltage after a few minutes, so maybe the miix didn't have that limitation. Once again did I say how nice it was to not have the fan? Battery life: The Miix by far. It slept and stayed asleep and consumed almost nothing while asleep. While powered on it wouldn't take too much power, a reasonable amount IMO. I feel comfortable I'd get a solid work day out of it. The SP4 by comparison was crap, the fan would come on randomly and start going nuts, the battery would be pretty bad with the screen on. It would often not sleep and usually when turned on would show it had ran down the battery, once in a while it would turn on in my bag and I'd get to work and take out a boiling $2100 piece of metal, not good. Upgradability: Huge plus to the Miix for this. The back pops off with 6 screws. You can put in a brand new M.2 SSD, a 512gb evo 850 is $177 on Amazon. You can put in a LTE antenna and there is even one on their parts list already, although I have no idea if the antennas are prewired, or available for purchase, and there is the issue of a SIM slot as well. Still just upgrading the hard drive is huge. You can really save your money and get the M3 version for I think $749, add $177 and have a 512gb hard drive and you save because the keyboard comes with it. Verdict for me: The SP4. Mainly because of 2 reasons: 1) the Keyboard on the miix is awful. I'm impressed with how much quality is packed into the tablet itself, but am dumbfounded why they cheaped out on the keyboard. Still, I would have forced myself to accept it if it was only backlit, a completely stupid decision IMO. 2) the customer service: Having issues with my keyboard being faulty made me realize what a pain in the butt it was going to be to service this thing, especially with the fame Lenovo has as being terrible at customer service. Versus just waltzing into a MS store and having them do whatever it takes to make me happy. Once you get used to that kind of service it is very hard to go back, let me tell you. Anyhoo some pics... EDIT: The cheapie forum will not let me upload files because they are too large, time to get the forum off of hamsters.