WARNING! Some LEGO gets attacked with a knife in this post!
Since building my permanent track, the one bit I was never happy with was the transition from the ramp to the run out, many 'Heath Robinson' type bodges was used with various levels of success until today when I had a very rare brainwave.
Idly fiddling around with a LEGO baseplate, I realised the gap at the bottom of orange track is exactly 3 studs wide and is also thin enough, when turned upside down & cut to size, to slide beneath the aforementioned orange track.
It also occured to me that the baseplate would have enough flexibility, yet at the same time, enough rigidity to make good transition pieces.
The baseplate I used had a length of 32 studs, these base plates come in various lengths, the largest I've seen is 48 studs (there may be longer out there, I'm not a LEGO expert), so you can choose a length to suit your particular needs.
Anyway, four strips of 32 studs by 3 studs were cut out by using a steel rule and making several passes with a hobby knife, these were then screwed down in the appropriate place.
The end result has given me a sturdy & smooth transition that I am very pleased with and was very simple to achieve.
I was also able to make some 6 studs by 3 studs track joiners with what was left over.
I hope this may prove useful to some of you.