Alcheng, I run Swifts with 15 mm spacers all around. I am very happy with the setup froma looks and performance point of view. I do not know if the alignment is impacted just by adding spacers because I always align after anything done to my suspension. Alignments only cost me the time it takes to drive to the shop and wait - maybe 1.5 hours total.
These two shots are right after spring installation:
This is a few months afetr spring installation and after they settled:
