I thought I'd talk about my experience testing v0.15.
Tournament
I love tournaments now. My settings are four teams of four participants who are assigned randomly. Tournaments have been shortened to three rounds, so it is sink or swim. Sometimes I get frustrated when I aggro 3-4 (i.e., a full team) opponents who try to headshot me from across the arena, but that is my fault for allowing my companions to participate with crossbows pre-selected. Companions regularly finish in the top five, and I get defeated occasionally. Tournaments are largely balanced. However, I choose not to bet. Getting 2000 denars and 1-3 items, depending on how my companions do, is sufficient. I should test the tournament with making bets, but the challenge there is that you need to survive the round to get whatever you bet for—even if it is for two points. As a result, balance is there for someone of my skill and luck, so perhaps my choice to abstain from betting is cautious instead of principled.
Recruitment
The troop system was overhauled. You recruit troops of any tier instantly if the conditions, such as available recruits and relation, and cost is the factor that balances your ability to instantly recruit a higher tier army. The best troops form each faction—both Knights, Huscarls, Rhoduk Sharpshooters, and Veteran Horse Archers—require veteran recruits, which are currently provided in small amounts when you participate in tournaments. I hear that future versions will also provide veteran recruits through quests. Unique troops exist. There are three or so per faction, and many of them provide unique functionality. They require 10 relation with the location that produces them, which are towns or castles. The combination of cost and requirements encourage you to develop efficient armies with some lower tier troops. Obviously, this system will be overhauled once more when troops are redone in v0.16.
No Troop Customization?
This is a controversial change, but I promise that you get used to it. I miss leveling my troops, but you still form attachments to your troops because of their cost and rarity. Also, companions provide the outlet for relentless shaping of futures. Windy mentioned that limited troop advancement could be brought in the future, but that will be a bonus to an already good system. I enjoy the recruitment system as it is. If I want 20 Vaegir Guards, I can get them immediately. I still feel sad when they get shredded running up the ladder.
Morale
Why am I using Guards in a siege, you ask? I prefer single-faction armies, so I work with what I have. The morale system is continuously being improved to provide better balance. If you want a multi-cultured army, you need to focus on party unity with your companion's Leadership and kingdom cultural settings. Also, the Guards were a bad example. How about playing as Rhodoks, with their indomitable units, and adding the Voulgier as a shock troop? Single-faction play as Rhodoks is lovely, and the morale system provides choices to be made for both play-styles.
Companions
Silverstag continues to make companions compelling. The groundwork has been set for them to get abilities that provide flavour. Choosing companions can be difficult now because a lot of them provide great things, but, as always, you have to choose between them.
Itemization
A batch of new items were added by Dawgofwar. They have yet to be polished for release, so there are some inconsistencies in them. Also, they haven't been balanced against existing items. That process will likely happen soon.
The requirements for items have, in general, increased. Head and body armour has strength requirements, and they increase quickly. Medium armours require strength investment between ten and roughly 17. Heavy armour is for heavy warriors that have high strength. Requirements for weapons have increased slightly, but most of them remain accessible after moderate strength investment. Unless you're using 2-handed blunt weapons, which are for Warriors(tm), 10-14 strength investment will be good. Nearly all crossbows are available to everyone. My favourite for every non-archer character is a Heavy Crossbow because it is the most cost efficient crossbow (damage increase compared to true value) and nearly every companion can use them immediately.
Bandits
Dawgofwar's bandits are fantastic. They look good, have creative names, and are balanced. They are slightly easier, but provide rewards accordingly. Sea Raiders remain the best. Mountain Bandits remain similar. They're kited easily unless they are lucky with their thrown weapons. Forest and Taiga Bandits are less dangerous because far fewer have bows. I'm judging these units from the perspective of a small party and me on my horse. Generally, their melee combat powers are better.
Saving Villages
If you tend to have smaller parties like I do, saving villages from quests can be challenging. I often hire mercenaries to assist me. The challenge of a particular village fight can vary greatly depending on the bandits that spawn. Some mountain bandit Trappers are easy while mounted Highwaymen are a nightmare.
Deserters
I don't know if this will be fixed for release, but deserter parties are only recruits. They're good in the early game for leveling, but they are non-factors afterwards. I imagine this will be visited by Windy later on, and the desertion mechanics will be made into something unique. Warband, itself, is problematic because units that desert disappear, so the deserters you see are spawns, like bandits.
I think that is enough of my bantering on. If you have any questions, I can try to answer them without spoiling too many of the surprises or stealing the developer's thunder.