I agree with Assassin, it depends on the person. I have trouble getting to sleep in the first place (I did especially back when I was actively LDing, though that's just a coincidence and the reason is wholly separate from LDing), but when I wake up in the middle of the night, it's pretty easy to get back to sleep so long as I don't do anything too physical (nothing more than getting up to go to the bathroom with the possibility of going upstairs to get a drink), and I don't start thinking too much about any one thing (leads to long strings of thought that tangentially break off from each other at times but otherwise are ultimately the result of some interesting thought that acts like a catalyst, at this point it's very difficult to quiet my mind and I'm very much awake), and most importantly that I don't stay up any longer than 5-10 minutes... 5 minutes being the preferred maximum time of being awake. I've actually only tried WBTBs that have had me awake for more than 15 minutes a handful of times out of many, many attempts. I suppose you could say, then, that I exclusively micro-WBTB.

The reason this works for me aside from the most important step of a WBTB/WILD being actually falling back to sleep is that the speed with which I fall back to sleep can be very helpful. It's a bit of a double-edged sword, but after getting enough experience I finally got a feel for what I should do and it's helped more than hurt. I naturally wake up 2-5 times a night anyway, so as long as I remember to actually try LDing (which wasn't hard back then, it's almost all I thought about, and if I missed a chance I still had at least one or two more that night), I have a decent chance at success. Of course, even that doesn't change the fact that I may just fall back to sleep almost instantaneously upon waking up. The absolute best case scenario is the very rare times I wake up without even opening my eyes or moving a muscle (I can do this pretty easily when I DEILD, but I'm always exiting a dream I was already lucid in when that happens). If I just lie there and keep my thoughts blank and feel hazily relaxed, my body (for a lack of a better way of putting it) goes back to sleep within seconds, without enough time for me to actually lose consciousness. Either I go straight into a dream from there or stay conscious through REM Atonia, which isn't an issue since I somehow got lucky enough finding a technique that works for me that allows a near perfect success rate of transitioning into a dream from REM Atonia.