>Legion champion with Paragon prime bonus
>WS 7 and 6 attacks
>Cheaper than a praetor
If champions still could take any melee melee weapon instead of a paragon blade there wouldn't be a reason to bring a praetor. Besides master of the legion I guess. That special detachment a legion champion unlocks is also neat. One retinue, elite, and heavy support slot. It basically has everything you need to bring some elite melee in one detachment.