I ordered a sample pack for my first order. I only performed research with Rilmaz. The quality was so good, I didn't see any reason to look into the others. My second order was placed on a Monday night and shipped Tuesday. By Friday I had the same amazing quality of Rilmaz as I did in the sample pack. The price per quality of product is unparalleled. The only concerns I had were addressed in an email in a timely fashion. Seriously, this vendor will work with you! I won't be looking into other vendors for similar research materials. I am a RiftChems customer for life!