The PVC may be a better pipe.
Although, there is a lot of ABS out there that is working fine. Like any product, there has been some batches that vary in quaility.
If you are replacing because of a cracked fitting, by all means use the PVC.
They make a PVC to ABS glue for the conversion.
The pipe sizes and fitting sizes are the same.
: I am adding a bath to our house (2 sinks, shower, tub) and would like to use PVC for the drain system.
: My current system is ABS. I know you are not "supposed" to intermix the PVC with ABS. However a few people have told me that the ABS does not last as long and will begin to crack and leak (as the ell at my master toilet already has).
: If I'm going to have to eventually replace all the ABS, wouldnt it make sense to plumb all the new with PVC?