I will emphasize this again, because I think its important. The camera is JUNK an should never be used for security or evidence purpose. The resolution is terrible. Instead if using 3 of these, you can get a 2mp hikvision. The motion detection is horrible and will give you tons of false triggers. Unlike the hikvision that has line cross detection, intrusion detection as well as a built in poe sensor. The night vision is terrible on the dlink as well. If you want and entry level camera for 20 dollars buy the top-201 pinhole. Spending any money on the dlink is a complete waste. I feel physical pain when i see folks spend hard earned money on this kind of trash.
Not sure why you fixated on the sd card slot but here goes.
Since you love running wifi which is a terrible idea to begin with, you need to come to the realization that, wifi is not reliable and therefore if you are using the camera wifi, sd card slot is a must. There are other reasons why sd card slot is nice, hard drive failure, power failure..for example, you can run your all cameras off a switch attached to ups via poe (not available on the foscam or dlink)...this will give you MUCH more record time than running your
blue iris pc on the same ups....the cameras will continue recording to the sd card.