I don't think it really matters after all.
If you have good talent they can perform well in a 4, 6, 8 sided ring. If you have bad wrestlers they wont be better by changing the ring. So I think the product didn't suffer at all, in fact, I think it benefited TNA Wrestling in general.
Casual fans that watched TNA Wrestling might looked at the six sides ring and thought it was unprofessional, or at least, 'cheap'. The big wrestling companies all have four sides, and the reason why is because there is a rich tradition behind it. I'm not saying that TNA should erase the memory of their fans about their past in the six sided ring, because they did have great matches but I think in the long run the four sided ring will help them a lot.
If you have good talent they can perform well in a 4, 6, 8 sided ring. If you have bad wrestlers they wont be better by changing the ring. So I think the product didn't suffer at all, in fact, I think it benefited TNA Wrestling in general.
Casual fans that watched TNA Wrestling might looked at the six sides ring and thought it was unprofessional, or at least, 'cheap'. The big wrestling companies all have four sides, and the reason why is because there is a rich tradition behind it. I'm not saying that TNA should erase the memory of their fans about their past in the six sided ring, because they did have great matches but I think in the long run the four sided ring will help them a lot.