My 05 Tundra tranny is sealed. I don't doubt Toyota reliability. I'm just not sure if I have that much faith in the fluid. I think I'd rather have a dipstick and drain plug.
They have drain and fill plugs, no dipstick. I won't let my tranny go 100K either. At 30K I'll have it flushed/filled with new fluid and filter. Call it $100 peace of mind.