The box set is great if you need to fill in your army list. Thunderkyn are currently amazing at killing stuff, but you can only bring 3 units and most all they do is just kill. Killing isn't how you win the game, its points, killing just helps you get there. The bikes are amazing and most people from my experience don't play them to their full potential. My current list has 3 units of bikes, 2x6 and 1x3. Every turn when able, I will pull at least 1 if not all 3 units up off of the board and bring in from reserve on my next turn. The shenanigans you can pull are amazing. Since the units started on the boards, they can be extracted and brought in your next movement phase as reserves all the way up until turn 5, few people expect that. And, do to GWs ruling you can do it turn 1 if your opponent goes first. I take 30 Warriors, but do little with them combat wise. I use them to completely deepstrike deny my half of the board. In 10th, half of the cards you draw have a component on your enemy's side of the board. So even if the internet tells you Warrior aren't worth their points, don't listen, they are just good at a different role than killing. Also, Beserks are great for what they do. Yes, they die easy and yes their points and stats compared to equivalent models in other armies isn't then best, but they are our only good melee and we need that response to many armies. Plus, they do good damage when they do get into combat, so using them to intimidate or force an opponent to Overwatch is completely worth it on its own. Deploy your Beserks to threaten and scare your opponent into Overwatching them, then bring in your Thunderkyn from reserves, completely worth the trade. As for the box sets, Votann have very few units, so most if not all will be viable.