For me the 7800 XT is the most disappointing out of all the 7000 series cards, it's the only card in the line-up to have fewer CU's than the card it's replacing.I had been waiting on the 7800XT to come out to replace my GTX 1070, I will wait on the reviews, but I feel that it will me more of a disappointment than a surprise.
At most it should be called a 7800 (non-XT) as it's closer to the 6800's (non-XT) 60 CU count than it is the 6800 XT's 72 CU count. AMD have left a massive gap in their line-up (ignoring the GRE) you have 3 cards separated by $230 and 28 CU's. The price and CU count of the next card in their line-up increases by more than the gap between all the cards under it.
Like you I'm going to wait for reviews but I'm expecting to be disappointed, given the current climate I'm sure some reviewers will say it's great to have this sort of performance for $500 while totally ignoring that you've been able to buy 6000 series cards at that price with that sort of performance or better for sometime now.
AMD really need to release a card that sits between the 7800-7900 XT's.