I find that if someone isn't prepared to give you specific reasons for why they're saying what they're saying, they probably don't have a logical explanation.
The subs you're looking at are at the lower end of what's available and the problem with them is that they won't be able to take their rated power long term without distortion, let alone their "peak" power... which is a completely useless parameter to begin with.
In the end, there are some subwoofers at or near that price point which will take their rated power cleanly and will last for years. I would look into either the JBL GTO series or the Sundown E series. Both are quality budget woofers and both will take more than they're rated for. I know because I've run a GTO ten on a thousand watts with no ill effects... long term. As for the Sundown Es, I have no experience with them but I've also not read a bad thing about them at all. And... I do own some of Sundown's higher end drivers.
