It's funny, there's big-time disagreement about this. I'm with you in liking the other guy, he just oozed way more personality. But others didn't like him. Either way, he only got recast because he took a leading role in an action film.
Also agree that the Dragons were good, but like you, I'm prepared for disappointment for the battle(s) at the Wall. Their budget is pretty good, but apparently not enough to do the large-scale battles justice.
Think the Dragons will get to King's Landing in about 5 years.