Oh, maybe you're seeing some of the "upgrade fever" posts here in the Rumble Club and elsewhere in the forum. Personally, I think it's a lot of "greener grass" dreaming. Or maybe they just got a few bucks burning a hole in their pockets, or something. Don't recall anyone saying there's anything wrong with the stock speakers, just "might be better" to upgrade.
If that's your situation, checkout this thread. I think the takeaway is "might be better, might be worse".
Fender Rumble 115 v3 Speaker Upgrade to Eminence Kappalite 3015
Hth