Wild plims are concidered the best pollinators for hybrid plums hands down. HYbrid plus are said to have better taste then wild but ive also read some people having a good wild plum fruit as well.

If you have the space, why not another wild plum and a few hybrids?

I've tried some wild plums before, they were sweet with very astringent skin...also very small. Excellent pollinators. I think one reason i get such heavy fruit set on my hybrid plums is that there are large thickets of wild plums near my home. Hybrid plums are more like Japanese plums. Large and juicy. Some have very good flavor.

Wild plums can be good. They are as mentioned very small.
If they are growing wild, I would leave them. If I was buying and then planting the tree, I would stick to the domesticated varieties.

Thank you for your replies. Can anyone suggest any hybrids they've had success growing (& eating)? Hoping to plant 1 or 2 hybrids and another P. americana this fall. Thanks!