My ABS pipe also "felt" somewhat lighter than the seemingly heavier "feel" of PVC.
There is no comparison between the two, both in lab testing and the real life testing on my plow. None. ABS blows PVC away.
OK, so the pipe I purchased is ABS, Schedule 40. It feels flimsy ("light weight") compared to the sched 40 PVC for sure, but I don't care how it feels to my had if it is much less likely to shatter in the middle of a snow storm. No new snow forcasted for the next week or so.