Pure combat DD are equal to pure combat fighter oriented prestige classes in my mind. This means no vampiric touch though since you are capped at 1st level spells. But you get enough str so that your AB equals a fighter type, your hps are only marginally worse since you get con bonuses, you gain natrual armor, natural attacks(cool with multiattack feat in MoTW), and eventually, natural flight, immunity to an element, immunity to paralysis, immunity to sleep(yep this one is lame), and a once a day breath weapon(generally lame but it does come in handy vs certain foes), oh and natural reach which rocks especially with combat reflexes especially if you also use a reach weapon, oh and large size weapons have a bigger base damage.
By the way you can take up to 4 levels of bard without sacrificing any AB, you lose some hp, but you gain more spells, including some cure spells(think wands),and you gain music abilities based on ranks in perform and not level many of which are cool, and at 4th level useable 4 times a day. If not going for a pure combat guy, 10 levels of bard gives you some nice spells, great music abilities, and are still a good combatant, just not pure fighter good.
We had one focussed purely on combat and he worked just as good as the fighter/weapons master in our group. Totally diferent style but just as effective.