Both of your choices have comp. airport shuttles, and many other casino hotels do too. What kind of "nice" are you looking for? I've no problems with the Harrah's suites and even the regular rooms - but then again I don't spend much time in there besides sleeping.

Haven't stayed at the Grand Sierra, only when it was still Reno Hilton. Its location is away from downtown and the other casinos. If you stay at Harrah's you can walk and visit the nearby casinos so that you're not stuck to one.

Harrah's steakhouse was good; the sushi bar was not. They have a quick and very good Chinese place by the Asian pit, a cafe, a good buffet, and an Italian cafe.

The nearby Siena looks pretty nice, if you'd rather pay instead of having more bankroll.