I'd compare Unleashed to Mindcrack without Gregtech honestly.
Whoever made the Unleashed pack had a great sense of mod balance IMO (N. Ores and Reliquary).
So what's the main pack now? (Unleashed / Ultimate / Unhinged (i doubt unhinged, it's a tad too tedious))
I'd like to think it's unleashed because there appears to be (slightly) less controversy surrounding it.