The wiki is messed up a bit. Here are links to the individual pages.
Why play a runepriest :
Runepriest are a mix. They straddle several roles, often choosing which role they want to accomplish each turn. This makes them good primary leaders in small parties, or secondary leaders in large parties, where they can fill in the gap as needed. They also hybrid extremely well. Able to supplement nearly any role, and loosing very little, they often end up the better for it.
*Recovery: While it's still above non-leaders, they are worst amongst leaders. There basic leader power adds little to healing, and the powers that do heal, are often just for a surge, or a small amount. They have little saving trow granters, except those which come from feats (mark of healing).
*Buffing: Runepriest always have some kind of buff going, and while they are individually small, they can easily have several going at once, which can quickly add up. It's also worth noting that runepriest often benefit from their own buffs.
*Toughness: With either Scale + Shield or Scale + Con, or Hide/Scale + THP, and the occasional self buff, runepriest have no problems in the front line. There as tough as most defenders (possibly tougher).
*Damage: Solid |W| powers, the ability to buff themselves, as well as a psudo-striker feature, runepriest can dish it out.
*Control: While there are many debuffs to put on enemies, most are just buffs in disguise, very few are AOE's, and except for some dailies, they is little to actually hamper enemy efforts.
*Simplicity/Versitility: Runepriest are probably the most complex class to play. You have to make about 2x as many decisions as any other class, and each decision is likely to be another effect to keep track of. However, since you can make such decisions, runepriest can be a sub-defender on one turn, blocking a path to a squishy, sub-striker on another, laying out some damage.