That Lords of War tournament sounds pretty interesting.
I would love to play a AoS tournament but Sheffield is decidedly empty when it comes to that. The most active wargaming shop tends to run other systems or 40K and emailed me to say no plans to run a AoS tournament
I quite liked the other system although very small beginning battles (I get that that is the point). The extra points for buying stuff put me off although shops are businesses so I get that as well. If I was to choose between the two the lord of war would win.
I like fighting against named characters, I recently got murdered by Thanquol (only had state troops and he was lucky with first turn) but taking them out of the tournament arena is probably a good idea. I also like the fact you can only summon units that you have selected in your army and can't summon a summoner.
Best thing of both is that huge numbers of models are not required. I'd be pretty happy to take my state troops detachment (and a cannon) down to either of these and see how well I would do.