Optimas are better in some respects, but worse in others. They tolerate abuse that will destroy conventional batteries. Letting them sit for months without charging them is no problem.

They charge more quickly because of lower internal resistance.

On the downside, they are very small capacity compared to conventional batteries in the same price range. Only 150 or 155 RC, compared to bigger TM batteries at 225RC. That's a huge difference if you troll. More than an hour of run time at a medium speed. Another thing that takes some getting used to is the discharge curve. When they start to go dead, they do it quickly with very little warning.