There is a general appreciation that Kings of War is more suited to being a tournament game than Warhammer Fantasy was. There are a number of factors that allow you to make that assertion:
- Single person focus turns
- A building block basis to army construction e.g. Set size units, limited special rules/abilities
- Generally tighter ruleset with proactive Rules Committee
- Limited magic system
- Restricted customisation of individuals and units
- Greater apparent external balance between races
- Introduction of time factor
Certainly I have found the game more balanced and I find it rewarding from a focus on tactics. That's not to say there was anything wrong with Warhammer Fantasy. Eighth Ed was the most enjoyable game I have played but it suffered from balance issues - both external and especially internal. The size of the player base and the growth of the Internet meant that any balance issues were quickly identified and this resulted in most efficient net lists being arrived at. The goalposts could be moved by comp but really that was all comp did.
However a couple of complaints that I've seen emerge are:
1. Fluff - people are missing their Warhammer fluff. I understand that as I loved the fluff, bought the sourcebooks, read the novels etc. However a lot of the people that are missing the fluff either have forgotten the criticisms they had of particularly GW Fantasy fluff (rose coloured glasses definitely deployed) or haven't read the Mantic fluff. Conceptually I find the Mantic fluff no less engaging than the GW fluff. However it has 25 years of less development. To most of us the characters are underdeveloped but that's a time thing. Mantic are trying to bridge the gap through the release of the new sourcebooks on a regular basis.
2. Lack of Army Customisation - one thing a lot of people liked with Warhammer was the access to magic items that allowed them to build their "special" character. In reality this meant they liked taking a 1+ Rerollable AS Lord who also had a 3+ Ward Save rerolling ones. Or putting Banner of the World Dragon on a unit of White Lions. The only real customisation was whether you had 27 or 28. In KoW the customisation is less due to the building block approach -set numbers - the limited number of Artifacts all of which are common and the limit of one item per character or unit. It's funny how magic items aren't fun when every one can use them. I would say also that the lack of customisation is a bit of a misnomer. I have been playing a Ratkin army and the most common item choices in a lot of armies - Caterpillar, Honeymaze, Ensorcelled Armour, +1 to hit, +12" range or +1 Piercing aren't things that I would ever use.
3. Sameiness - one charge are that because of the building block approach games are very samey i.e. My Horde of CS(1) 4+ De fights your unit of the same stats. I've found that very rare myself and believe that there are a minuscule number of times equally matched units fight each other. Even in this situation the player who has been able to concentrate force into a vital area of the battlefield will win. The use of scenarios is also a winner for me. The scenarios are sufficiently different that they require different tactics to be employed to do well. Contrast this with "competitive" Warhammer e.g. ETC up to 2014 where a lot of TOs went out of their way to remove scenarios and play only Pitched Battle.
Yes if you have a small group of players in your area you will likely have a number of repeat games. However I'm not sure how that is any worse than the same number of players playing Warhammer. There are a whole swathe of armies I've never seen on table and I look forward to try out my skills against these new challenges - I mean WTF do Night Stalkers do?
4. Timed Games Are Anti-Social - the charge being that the introduction of time pressures means that there is less opportunity for social interaction. I can see the argument but I also believe that 50-60 minutes for each player allows you to have a well paced game with the usual banter. Personally I'm not missing the 3.5-4.0 hour games that occurred in Warhammer. I think the time pressure is a great addition as it forces you to make some decisions and ultimately has a benefit for those who make quick, correct decisions.
There's no right or wrong answer over what you should play or not. People have preferences and my view is that they should go with their gut. If you like Star Wars play X-Wing, like skirmish then AoS, if Imperial Knights are your thing play 40k etc. But the most important thing is just play!