I don't think it's awful, maybe I'm being mild because they now have the Night Ranger guy with them and I like Night Ranger. That said, the solo is played by Reb Beach and I always preferred his style to Dough Aldrich's, so you can probably say I like Winger too!
I do miss Glenn's backing vocals (emulated in part) and funk bass though.
So WS does a Purple covers album - probably a wacky idea their Italian label Frontiers came up with.
My judgement is probably also tainted by the fact that I don't think Stormbringer was even originally such a hot song. By that time Blackmore was running out of ideas, stuck in a messy divorce and saving all his good ideas for the first Rainbow album. The Stormbringer riff sounds a bit throwawayish to me, like something Blackmore jammed to warm up. There is song material on Sormbringer (the album) that is much better than the title song (Holy Man, Gypsy, Soldier of Fortune and Hold ON, even Love Don't Mean a Thing come to mind). It's not a bad song, but not in the Burn or Sail Away "Mother of all Riffs"-category for me.
At least DC doesn't disown his Purple heritage anymore - around the time when he conquered America in the late 80ies, he acted and sang like he had never played with them, but with that other obscure Brit band, the Del Nileppez they were called, I believe.