Repair costs in 1.03 were a problem because the loot wasn't enough to cover the repairs, no matter if the character was killed or not. In experience penalty the player can go out and recover what just lost. Completely different.

Builds are a matter of choice. The same can be said of no experience penalty: The only viable option is glass cannon. Which is not true. The better build will always be the one that maximizes eDPS, and that's independent of penalties.