I love this wine. Typical flavors you get from the wine are dark, dark fruits like blackberry and blueberry. Sometimes a "fakey" Welch's Grape Juice component. Folks who don't like the style often point to the "jammy" and extracted qualities of many of the wines. But, nobody can say that they're not packed with flavor. There can be herby and dusty notes as well. The younger wines can be quite tannic, but are much less acidic than wines like sangiovese-based wines. Unless they're in perfect balance, most taste better with heartier foods. A Cilurzo (Temecula) 1985 PS got me "into" wine. Unfortunately, the wine they're now making appeals to a "sweeter" palate.
As you know, it's a French grape, Durif, that has fallen out of favor there, but makes very expressive wines for those who love growing it. As far as ideal growing conditions, the oenologists can weigh in, but a few that I've had, in roughly ascending price:
Bogle, $. Lots of folks like this, but I find it overly astringent.
Jewel, $. Can be found for under 10 bucks, and a nice wine to get you in the door. Look for it at Cost Plus World Market.
Concannon, Central Coast, $. I like it better than Bogle, and it's dominated by red fruits. Not typical Petite Sirah, but good stuff for the price.
Carmen, $$. A South American wine that is a fantastic buy. Pick it up if you see it. Under $20.
Guenoc, $$. Okay, but some swear by it.
Girard, $$. Delicious. Pick up the 2004 if you can find it, I think it has classic PS flavors, and won't break the bank, about $25.
Eaglepoint Ranch, $$, Mendocino. I loved the 2003 so much I bought a case, and I've read the 2004 is richer, but more tannic.
Foppiano, the ones I've had are too tannic/oaky for me.
David Bruce, $$: Good stuff, not my favorite, but some love it.
Rosenblum, $$, $$$: Delicious. They make wines from several different vineyards, and all are good for the price.
EOS, $$. Mmmmmm, good, very rich and jammy.
Elyse, $$$. Well made, if you can find it.
Stags' Leap, $$$. A nice bottle to try, about $35-40.
Turley, $$$$, Whoah. If you can get your hands on a bottle, one of the gold standards. But, expect to pay about $100 bucks.
My opinion is to do a little taste-off of a few bottles. Might round up a Bogle, Girard, and a Stags' Leap, which are all commonly found.