I have used ramps on all the LBC's that I've owned: Spit, TR-6, MGB and GT-6.
Never had a taildragging experience yet. Have also backed most if not all of
the cars onto the ramps when needed. The only vehicle that I have had a
problem with getting on the ramps is my wife's Saturn SC2 - the front facia is
too low and scrapes on the ramps.
I have had problems with the ramps sliding when driving up on them. I solved
this by using a star chisel to punch a couple of 0.5 in. diameter holes (about
1.5 in. deep) into the garage slab. When I want to use the ramps I drop a bolt
into each hole to prevent the ramps from sliding.