Any long term potential seems very limited when high noses are apparently to be banned for 2014? That would limit "long term" to late 2013, and they may need that long to start improving the thing.
So you think they should abandon all the resources and time they spent into a new philosophy which once they understand has long term potential?
I think a switch ASAP to the 27(B) would be the best, combined with a shift in focus to 2014. I think this season is lost no matter what, but the -28 apparently has so many issues and things the engineers are scratching their heads about that I suspect it may be better to switch to -27 to obtain reasonable results and get drivers and team back in a comfort zone. Meanwhile, the design department can start early on 2014 instead of attempting to fix the -28 for most of the year, while doing only the minimal amount of updates on the old car.