I have played the GHQ rules twice. But having only played one other ship-to-ship battle in my gaming life, I have very little experience with naval wargaming to provide a base of comparison.
I was not the game master in my games. So I can't say how well the ruleset reads. But I did find that it plays well.
Our games were fluid and fun. I managed to run a squadron of capital ships, including HMS Hood, PoW, and two cruisers in my second time playing. The vast majority of our time in the game was spent maneuvering and shooting, and our thoughts were on tactics, observation of our opponants, and efforts to coordinate between our plans and their observed behavior. That's a good thing!

Far better than games where the majority of one's time is spent flipping through rules, debating the interpretation of arcane language, or scanning a small stack of "quick reference sheets" that each have 37 different charts or tables.
Our games were surface-action only. We had no airpower, nor submarines. But by the second game we had alreay used primary and secondary guns, torpedos, and ramming. So the games were fairly complex. Yet they played very well, and it never felt to me as if the rules were a burden.
Afterwards, when we put the AAR up on this forum, there was some discussion about the range of the guns. On that point I think the rules were fairly weak. It seems that the longest-ranged guns involved in our action, according to historical research, were the shortest-ranged guns according to the rules. So also some of the shortest-ranged guns historically were given the longest ranges in the rules. Specifically the German 11-inch guns of the sisters were actually very long ranged guns, while the British 15-inch guns, while respectable in tube performance, were in low-elevation mountings in many of the older British battle-wagons, giving them less than half the range of the 11-inchers in the sisters. Yet the rules simply give range by caliber, and bigger guns get longer range.
So I would rate the rules as fun and playable. If you want technical accuracy you may have to make some house mods.
Hope that helps.