Head-off-engine valve spring compressors

Getting ready to get one. Have been looking at the Proform 66832:
https://www.proformparts.com/product-exec/product_id/304/nm/HEAVY_DUTY_VALVE_SPRING_COMPRESSOR_

and the KD 380:
http://www.mytoolstore.com/kd/kdengi13.html#380

Anyone have any good/bad comments on these? I wonder if the KD retainer jaws will have any issues on heavy/dual valve springs. Tnx!