Pine straw is as good an organic mulch as anything else you want to use......it just has a bit of a reputation for flamability so maybe not highly advised in areas where wildfires or brushfires are common. And it is most common where the source material - long needled pines - are prominent, mostly in the southeast and midAtlantic states.

But there is nothing to it that would either discourage/slow plant growth or boost/stimulate plant growth. That's not what mulches do, although any organic mulch can add to soil fertility in the long term.

Solo, I'm not crazy about it because it stays so fluffy for so long, and a thicker layer is needed for it to retain water, my primary reason for mulching. It may work better at doing that after it's been there for a while. I haven't done enough with it solo to know. It's also hard to get it to look flat. A weird thing to be bothered by, but can I help it? Nope.

I also tend to futz around constantly, and like to easily access any given spot for whatever propagation or relocation experiment has stuck my fancy at the moment. If you don't do annuals or that kind of messing around as much, you might love it.

Bags of it that I do solicit since our yard doesn't generate any are great to add to compost, and to sometimes spread thinly with other leaves'n'such to help augment existing mulch, especially when any possible plants are dormant, so its' tendency to get on plants instead of under them when trying to spread it around isn't a factor.

Just keep it off of paths and sidewalks - it is very slippery.