It's only recently that I have come to think that "Best of Both Worlds" doesn't actually involve the heroes or the villains insanely avoiding warp within the Sol system at a time of great hurry.
Sure, Riker commands slowing down to impulse initially. But there's nothing to say he wouldn't go to warp afterwards again. Also, the Borg appear to be dropping to sublight next to all the big sights, firing at them, and then continuing their penetration towards Earth - and each leg there could involve warping, from Saturn to Jupiter, from Jupiter to Mars, from Mars to Earth.
Yet clearly Riker isn't making the expected sort of headway even if warping all the way to Earth: the trip is said to be at just twice lightspeed or so. But that in turn is consistent with warp being slow close to Sol - not forbidden, but quite possibly often impractical because it's little better than impulse.
Where this issue would be a big deal is "By Inferno's Light", in the sense that Dax and Kira banter about it. Where it probably isn't is ST:TMP even though Kirk "risks" going to warp as far out as Jupiter, since the risks would be inherent in him flying a ship with untested engines anyway.
But where it may be a big deal silently is all those cases where a sublight shuttle is the chosen means of ferrying folks to and from the outskirts of a star system: perhaps the mothership avoids warping all the way to the destination because warp in that particular system (and during that particular moment of nasty subspace weather) would be infuriatingly slow.
Certainly Scotty in "Elaan of Troyius" makes it sound as if insystem travel at less than warp is practically unheard of. In contrast, our DS9 heroes always seem to putter between the station and Bajor at impulse - but that system is explicitly known for its foul subspace weather, perhaps almost uniquely so. Is that why Dax worries in "Inferno"?
Timo Saloniemi