The prices will be worse until the higher speed link problem is resolved. That speed advantage allows the HFT firms to have less risk, that less risk gets translated into lower spreads (ie better prices) on the exchange.

Conversely, the slower links cause the firms to take on more risk, for which they need to make more money, that happens in the form of increased spreads.

μs or ms. As I mention below, there may be a little delay as people failover and reassess their view of the book, but that's all.