I have a Rheingold which I grew from a cutting from a small bush in a neighbours garden. He trimmed it like a hedge each year but using secaturs not to spoil the shape. I have mine in a pot and neither mine nor his are threatening to grow to anything other than what we want. I think with these trees you do need to take the size at ten years with a pinch of salt and look at the longer term picture. If you are very strict with them once they reach the size you want you can restrict their growth by annual pruning. However do not cut back beyond the green growth or you will end up with a scar on the tree. GC's sell conifers as Dwarf whether they are true dwarfs or just slow growing. I remember reading of one which was sold as a dwarf but grows to over 80'. BUT it takes 1500 years to grow to that height because it is slow growing. I wouldnot worry too much. I also have Boulevard which is a slow grower rather than a true dwarf. All three are varieties which can be trimmed without losing their looks.

Thanks Sheila....I will plant them where I wanted to put them then :)