First of all, if the budget is 6000 yuan, don't consider the camera. The camera at this price is not as good as the card machine, so from this point of view, 700 d is recommended;
Second, look at what you shoot. If continuous shooting is not required, such as short films, MV micro-movies, SLR is better than professional cameras, but if there is no basis for SLR operation, it is estimated that it is a bit difficult to use, focusing, aperture, sensitivity, white balance and so on. You must grasp it well. If you are confident, then the SLR will be fine; If the quality of what you want to shoot is not very high, but consistency is very important, such as meetings, parties, celebration scenes, etc. Even if it is difficult to interrupt later, if you want to shoot for a few hours, spend more money to buy a camera;
Third, the CF or SD card file system is relatively fat, and it doesn't support files exceeding 4G, so the SLR will automatically stop recording every 12 minutes. This is a problem, and the SLR can't automatically follow focus (some wonderful machines seem to be able to follow focus), so keep your eyes on the LCD screen, and if someone moves back and forth, turn the focus ring ... The third point seems a bit repetitive, so you should think about it.
You can ask questions if you have any questions. As for battery life and lens, think about the first three questions before you consider them.
Some people say that "SLR photography is always a guest appearance, congenital …", which is completely nonsense. We shoot advertisements, feature films and high-end weddings, all with SLR. Most shots are taken by the live host, mainly SLR. Have you seen Wengu 1942? There is a SLR lens in it.
To put it bluntly, if you haven't touched a camera or even a SLR, I suggest you consider a camera instead of buying a SLR. That won't work.