hi strapper,
yes, i have. in the shop where i worked previously to opening of my own, the owner used exclusively dba. but when the distributor had a backorder on dba, he purchased the ebonite powerhouse material. unfortunately, we encountered the same "cracking" problems and yellowish tint. we tried different pumps, measuring cups, temperature control, etc...but to no avail. eventually, the owner went back to dba.
within my shop and at the suggestion of another pro shop owner/friend, i tried and am still using tech-line plugging material. i'm very satisfied with the tech-line products. imho, it seems that the tech-line material is more tolerant to preparation errrors and enviormental/humidity changes. the plug hardens clearer and the colors are more vibrant. i've had very few problems and when i did, it was usually do to operator error.
hope this helps.
rk