The X-wing doesn't stop dead in its tracks then explodes at all. And the only time we ever see ships explode any differently is when the camera is moving with the ship, which in this instance the camera is static. When ships get destroyed in the OT the explosion is static at the point where it is destroyed. Only in the trench run when we see the Xwings & Y-wings from a side view do we see them break up and continue on as they explode because again the camera is moving. Just look at the ships that are destroyed in the OT in the space battles and the majority of them the explosion will be present at the exact spot the ship was hit.

It goes from the most enjoyable scene to the most pointless scene of the movie just like that.

Most pointless scene? Talk about over exaggeration. This whole scene never sat well with me since 1980. It seemed pretty pointless and unrealistic. The Empire have just turned up and started a blockade around the planet. They are preparing to kick the rebels asses. So what do they do? They see the first transport and 2 x-wings heading towards them, with no other stardestroyers in sight, and just sits there and waits until it flies straight at it. Oh wait, what if it suddenly turned away from the stardestroyer? oh well, that one slipped by. Oh come on. If they are their to wipe the rebels out, which they planned to do with aerial bombardments, they certainly wouldn't have just sat there. They would have tried to destroy the transport and it's escorts. Vader knew Luke wouldn't be on one of those transports so they would have been just cannon fodder.

As it stood originally it just looked like an easy escape. There was no sense of danger apart from one stationary stardestroyer that was doing sod all. It wasn't a surprising victory at all. I never felt that the transport was in any danger of being captured or destroyed. I always wondered why they just sat there and so did a lot of other people.