I have found the two extra weights make the Ariel significantly stiffer. This summer I removed the weights for an extended period of time. During this period I was sailing a fully loaded boat (3 people and a bilge full of drinks) In that situation, I didn't notice a decrease in stability. However, when the bilge was emptied at the end of the summer, and while I was sailing solo, the boat was significantly less stable. The weights have been returned to the forward section of the bilge and I have regained stability.
If you are racing, you may not want that "stability" because the Ariel sails fastest with a significant heel (in my opinion). However, for cruising, and with guests, having the rail in the water may not be what makes everyone feel relaxed.
The balance point for the Ariel is about where the locker is. By placing the weights as far forward as possible in the bilge, they do not affect the forward/aft balance, but do help with stability. I use the eyes on the weights for lifting. By placing a line through the eye, they become relatively easy to lift out of the bilge and I don't risk smashing fingers.