I actually had a few bad incidents with just using tape by itself.
Splitting right on the edge and batteries flying out.
Plus a few times I was having to rush to get new batteries in my car to race again right away with a new set. I thought there has to be a better/easier/simpler way to do it.
As for added weight, I think the tiny buckle and couple pieces of velcro are negligible as far as added weight over using the same amount of strapping tape every time.
My driving ability (or lack thereof) makes much more difference in how fast my car is more than it weighing .03 oz more...
I agree about the velcro losing its "stickability" eventually, but with how the velcro attaches to itself through the buckle, it is actually a very strong attachment, even if I only had 1/2 of the velcro sticking together.