I like both games. But they do two very different things. TtS i very fast paced and you can play a game with rather large armies in an evening. And it is easy to learn. You can teach it to people with no wargaming/boardgaming experience in a turn. We play on a board where we have only marked the corners of the grid, so it is not as visible so the grid does not bother me at all. My main "issue" with TtS is that in combat you cannot really stack the odds in your favour. You charge in and hope to draw a good card and that your opponent does not.
I like combat in HC better, where you can stack the odds a bit with supports and/or a commander to your help the charge.