It should be more stable than 2017, many of the critical bugs that plagued 2017 have been fixed. Viewport won't be faster this time as far as I know, but overall it'll feel snappier. Some Unwrap fixes, many UI fixes too, faster UI drawing and window docking - actually they did a great job with the UI.
One thing to keep an eye on is Edit Poly modifiers, there were cases where vertex indexes in Edit Poly modifiers were shuffled resulting in different results between older versions, 2017 and 2018. Not sure if this has been fixed (probably in the PU that came out recently), but something to be aware of if you tend to use Edit Poly modifiers often.
Another known issue is that resetting a scene and loading another one may crash. For some people it's reproducible, others are not affected.
I'll be switching to 2018 once some projects are out the door, 2018 is the best reason to skip 2017 completely IMO. Like you I'm waiting for some of the free 3rd party plugins to be recompiled.