Probably I'm alone with this request, but letting aside the zooming by "drawing" a rectangle area and the ability to measure frequencies also for falling edges, I also miss the ability of LeCroy scopes to measure (y) values of all the channels for a cursor position. E.g. even the WS3000 will display the values for all channels for each of the two cursor positions. For the SDS5000X/2000X there is only one (y) value that can be displayed for one cursor. So to measure two values at the same position (e.g. voltage and current), you need both cursors instead of one. Which makes it impossible to measure more than two values, letting aside all four values at two positions. This is somewhat limiting in some situations, specifically for screenshots to document one or two certain states.
To illustrate this, here's a screenshot where I used to cursors to measure two different voltages at a specific position. It' s OK for this case, but to with two cursors measuring both (or all) values, I could have marked the start and end of that little dent on channel 1.
This being said, there's another great feature of LeCroy scopes which I miss on my SDSX5000, namely the visualization of the current signal rising/falling state that's very helpful when placing cursors. I.e. when trying to place a cursor on a falling edge, a LeCroy scope will help you find that edge manually by painting a rising or falling arrow at the cursor position. So if the signal is currently falling, the arrow fill be placed at the x/y position of the current sample, pointing down. If the signal is currently rising, the arrow will point up instead. So you can safely place the cursor in the middle of the edge without zooming in.