Despite widely publicized reports of unexplained battery drainage, the satisfaction ratings on Apple’s (AAPL) latest iPhone continue to hover in what ChangeWave research director Paul Carton calls “nosebleed territory.”

In a survey of 215 new iPhone 4S owners, 77% declared themselves “very satisfied” and 19% “somewhat satisfied” with their new phones. Only 2% were “disappointed.”

Given the margin of error in a survey like this, it’s hard to tell how much to attribute to the quality of the product and how much to the growing discrimination of smartphone users. The iPhone 4S’s 96% satisfaction rating is better than the iPhone 4’s 93%, but not quite up there with the iPhone 3G’s hard-to-beat 99%.

One thing is clear: None of the competing smartphones comes even close. In a June survey, 70% of iPhone users said they were “very satisfied” compared with 50% for Google’s (GOOG) Android, 27% for Microsoft’s (MSFT) Windows phones and 26% for Research in Motion’s (RIMM) BlackBerry.

Drilling down into the iPhone 4S ratings, ChangeWave asked users what they liked best about their new phones. Nearly half mentioned the Siri voice-activated personal assistant, followed by how easy the phone is to use (39%), the improved camera (33%), faster Web browsing (24%) and higher-res screen (23%).

Only 19% named the new iCloud service.

Asked what they liked least, 38% said the battery life was too short —  not terribly surprising given that the survey was conducted between Nov. 2 and Nov. 9, while the battery issue was still front-page news on Techmeme and before Apple issued the first software update to address (but not completely eliminate) the problem.

Even so, battery drainage didn’t seem to dampen enthusiasm for the iPhone 4S all that much. According to ChangeWave:

Two-in-five owners said they had experienced reduced battery life with their iPhone 4S (40%). But when asked how much of a problem this issue was for them, a total of 8% of all owners said it was a Very Big Problem and 20% said it was Somewhat of a Problem.

Only 8% complained about “excessive dropped calls,” which seems low given the reputation the iPhone earned while AT&T (T) was its exclusive U.S. carrier.

Looking deeper into that result, ChangeWave found that although the overall dropped-call rate on the iPhone 4S was half that of the iPhone 4 — 2.5% in November vs. 5.2% in July 2010 — some of the difference could be attributed to the addition of two more carriers: Verizon (T) and Sprint (S). In particular, according to ChangeWave:

“In a direct comparison of the dropped call rates between Verizon and AT&T in this survey, Verizon iPhone 4S owners reported only a 1.3% dropped call rate while AT&T iPhone 4S owners reported a 4.1% dropped call rate.

Hello, AT&T. Can you hear me now?

ChangeWave, a division of The 451 Group, conducts weekly surveys among a network of roughly 25,000 early adopter types. For more on its latest results, follow this link.