Annoying. I try to ignore it. The previews are just too slow. I'm not on a slow machine either. MacBook Pro 2.4ghz + 4gb ram. Comcast 12mbps connection too. Even on my i7 930 @ 4ghz it's not the best....
I explained before that I'm a fast typer. I can do 120wpm in those typing games, but I'm probably slower on average stuff... but still darn fast. Either way, I type fast enough where the results don't keep up with my typing.
For example, if I'm searching for "how to turn on autofill iphone"
The minute you start typing, it'll try to search. But the AJAX or whatever obviously isn't fast enough to research every character you type. So it might to a search on:
"how" then
"how to turn"
"how to turn on auto"
Here's the problem. The search isn't instant because there's latency and time for data to load. So by the time it shows the results for "how" and my eyes see it and my brain processes it, and spots result #3 as something I like, my hands are still typing away and I might be at "how to turn" already. By the time my fingers stop because I like result #3, Google will now process a new instant search result on what I typed, then giving me a new page of results.
Here's the problem. How do I go back? How do I know what the previous instant search was based on? Was it based on 2 words? 3 words? 1 word? I can't hit back like it was a previous search that I hit "SEARCH" on. I instinctively hit back, but that just puts me back to the main Google page. It's frustrating. I end up wasting more time this way because I slow down my typing to check on result after result.
To me, the more important feature the have is the autocomplete search feature. THAT by far is more important.