Ballasting. You don't have to ballast a round top water lure. The bottom hook and split ring will keep it vertical and it will "walk the dog". BUT, they generally work much better with ballast and when ballasted properly, you can work them and achieve a wide walk the dog sometimes even 18-20 inches wide glide on walking the dog. Also, a ballasted stick bait "moves more water" when it is worked and I think water noise when walking a topwater bait is a good thing. Added weight also helps with easy long casts. So, I think you should ballast the bait and I suggest that you keep the ballast weight about 1/3 of the distance from the tail of the bait. When the back end is heavier than the front end, the walk the dog action is generally easier and the back end pushes the front end when you give slack line while walking the bait. When you check your ballast, have your hooks and split rings on. When you test, the tail of the bait will sit down lower in the water but don't make it too much lower. Compare it to other topwaters you have for how it sits in the water. In the bucket of water, tap the tail end of the bait with your finger to see how tender the bait is.(tap...tail goes deep in the water comes up slowly, tap...tail bobs back up quick and perky)
Hope it helps,
Barry