The PG range are just a cheap range of brothers to the proper SM series.
PG58 to the SM58 for example.
They'll be better than most rubbish you'll pick up and will be fine to use live, yet I would recommend putting your money elsewhere. Especially if you're buying for studio purposes.
I would recommend getting [url="http://www.thomann.de/gb/the_tbone_mb85_beta.htm"]http://www.thomann.de/gb/the_tbone_mb85_beta.htm[/url]
Effectively a ripoff of the Shure Beta 58, but VERY well done.