David,
The negative effects on batteries of not balancing only become significant over time. Real-time measurements - especially with large cabling - will show only small differences between balancing or not balancing.
Of course, the negative effects over time will be greatest for RV'ers using their batteries for large current draws often (i.e. microwave, coffee maker, induction cooking, convection oven, etc.) and also for RV'ers applying large currents often for quick recharging. The imbalance is greatest in these situations, but it will still take it's toll on batteries only over time - just more so.
Read the entire article in the link that I gave. The reasoning there makes excellent electrical and battery long-term sense.
