My brother has owned a full-size SR9 for about a decade. It's been reliable for him and is easy to shoot accurately. It's a surprisingly slim and ergonomic pistol for a double-stack. The trigger is decent - very Glock-like, which is unsurprising. It has a low bore axis and very soft felt recoil.
The magazine disconnect and laughably large loaded chamber indicator are very unfortunate. The manual safety is tiny and not terribly easy to operate, but also unlikely to to be inadvertently actuated.
In may ways, the SR9 was superior to Ruger's current crop of semiautomatic pistols, such as the awkward Ruger American Pistol - especially in terms of ergonomics. It's a shame Ruger didn't further develop the SR9. They did offer a budget version called the 9E for a short time, but it did little to ameliorate the SR9's primary issues.
An SR9 version that ditched the magazine disconnect, awkward loaded chamber indicator, and offered an option for no manual safety would have been a very nice pistol indeed.