GoT is consistent when it starts, I believe it starts the first sunday in April every year. It is 42 weeks in between the finale and premier, so it does seem like a long time.
Quality television with such difficult settings takes time to produce. I am happy with how they do it.
The biggest bummer about GoT is the fact Martin has still not completed book 6 and it doesn't seem like it will be released any time soon. Many believe HBO is going to catch up to him before finishes the source material. I think things are going to get nasty between Corporate HBO and Artist George RR Martin.