Arcane Warrior is good. You can play it more than one way too.
It’s pretty easy to just use AW and still be mostly a caster type. If you wear the robes (Reaper’s Vestments), light armor (the Felon’s Coat), or stamina boosting items (like The Fade Wall as these boost mana on the Arcane Warrior) you can still cast plenty and then activate Combat Magic and join melee once your mana starts running low. The advantage of doing this is that you can still be a primary caster and have some melee fun in nearly every combat. The downside is that you are unlikely to be able to tank nearly as well as other types of AWs and that you really need those defensive sustanables like Rock Armor to avoid eating a ton of damage at close range.
The other main approach is wearing massive armor you can and keeping a lot of sustained spells up & have great AC. With that setup you are less likely to cast much. Instead you become a flexible tank that can heal, fireball, or whatever every once in a while but mostly auto-attacks and lets the sustainables make you strong. The advantage of this approach is that you can have insane AC pretty early and are nearly always going to end up being one of the most durable folks on your team. The downside is that you are no longer a primary anything. You don’t grab aggro as well as a warrior tank nor do you resist knockdowns & backstabs. You don’t cast as well as a less specialized mage most of the time. You certainly aren’t a DPS rogue even if you can do impressive autoattack damage. You are really strong and flexible … but you no longer really fit a clean party role.
It’s not too hard to stake out a middle ground there either. You can aim for stamina boosting heavy armor (the Warden Commander’s set from Warden’s Keep DLC is particularly good) or get a secondary specialization in Blood Mage so that you can cast away even when armored up. Alternately you could just wear good Medium Armor (Wade’s Superior Dragonskin or Dragonscale both grant very good AC while offsetting fatigue).
In play I tend towards starting light and then switching over to the heavy armor approach as I get better gear. Even moreso than most mages Arcane Warrior’s are really vulnerable to Templars and other foes that can get rid of their sustainable spells at certain points in the game. In melee the AW really needs those sustainables to be effective and when they go it’s a real pain, especially if your equipment isn’t great.
I also strongly recommend reading
Arcane Warrior Spellcasting on the DA Wiki if you want to play one. Essentially some spells require you to sheath your melee weapons to cast … and this can really slow down the character’s response time. I tend to aim for the spells that you can cast with weapons out more than not just to avoid this … but that’s not really mandatory at all.