Seriously this doctrine is quite useless, especially in 1v1.
The 'close the pocket' ability is quite strong but only useful on certain big maps whose design allows you to cut off an important ennemy sector from its HQ. In 1v1 and 2v2 there are nearly no such maps.
In addition, if your opponent is not completly stupid and do not takes hours to react, in order to use this ability you have to commit a lot by sending infantry or even tanks far into the ennemy territory in order to cut off the ennemy sector (and exposing you to flanking/mines).
Stormtrooper are quite fancy because they can pop up from ambient buildings, but are expensive and need a lot of munitions to match panzergrenadier's antiinfantry or antitank DPS (which are a T2 unit ...).
The sprint is cool, but you also have it for example in the Blitzkrieg doctrine which is I think way more stronger.
Most of the time people who use this doctrine (and even very good players) end up by just using some stormtroopers whose role would have also been perfetly fit by panzergrenadiers.
This doctrine gives you nothing very useful in late-game : no hotwitzer, no Tiger, no Elefant ...
The AI of upgunned stormtroopers is much better than pgrens becouse you can use their special ability, similar to the one thompson paras have, that completely melts any squad without a time to react, even a shock troop squad.