I've stayed at the Oasis practically every year for the last eight. I look forward to it each time, but this year it was just a little frayed at the edges.
This is a premium park, very nicely landscaped. I've never had any problem with the restrooms or laundry. Staff is always courteous and the security is good. The prices are not expensive when compared to staying in Las Vegas, though they are on the high end of Nevada RV parks. You can find them here: http://www.oasislasvegasrvresort.com/oasis_rates.html
A big change this year was that the shuttle bus went broke. I wasn't aware that it was a separate operation, and if it was, I think the Oasis should offer a service itself. Otherwise, you're nowhere near the city, although there are a few casinos within walking distance if you like to walk -- and run across highways. The front desk will call you a cab, which is pricey, and there is bus service. Considering the distance from town and the expense of getting around Vegas, I think you'd be best off renting a car at the airport if you're going to be there for a couple of days or more. I vaguely remember an onsite car rental service a few years back, but it's gone.
The front-desk only works about 12 hours (8 to 8, I think) so things are pretty quiet at night, which doesn't exactly scream VEGAS to me.
Positives include nice, wide spaces, beautiful landscaping, a well-stocked store and a quiet, relaxing place.
When I first started going there, the Oasis really WAS an oasis -- there was little development around it, other than a 7-11 nearby. Now there's a huge condo project that looks right down into it, so if you were thinking of sunbathing on top of your RV, think twice.
I noticed it wasn't very crowded this year, compared with the past, and the manicured grounds were just a bit less manicured than they were in my mind's eye. But I still really like this place, and I think it'll get back some of its sparkle when the economy picks up.