To say spindles RIDE poorly is illogical, A spindle DOES NOT affect your ride, It still has the same EXACT parts that control ride...ie; springs, shocks, bushings, tire, etc...spindles are solely mounting devices, the BT ones are raised up 2" for a 2" drop. They will mathamatically NOT change ANY angles, nor wheel positioning, what does change is the "arc of travel", it is tech 2" higher, so rubbing may occur, due to a later point of arcing...but if they were as bad as some guys state, no one would buy them, and they'd honestly be discontinued. (btw I have a set personally)
I recommmend a spring swap over spindle swap simply to get a more agressive rate for improved handling, and tighter ride. If you only do a spindle swap, and stay OEM 1987 springs, your 20 yr old springs that are not OEM rate any longer WILL travel too low, and cause rubbing, premature shock wear, tire wear issues, and a;ll things poor. (Atleast replace OEM w/ MOOG OEM rate/height units)
Also, Most reputable shops know that spindles do this change in wheel placment, and when you get aftermarket wheels, will account for this by changing the BS, most by 3/4" some +/- depending on thier experiences. I actually spoke w/ MHT regarding offset for Foose wheels, and spindle issues, and the were aware of this ongoing issue.
GC