it has already got to new zealand.
Highly doubtful. You cannot get 15ms from Asia to Europe or America unless you some extremely expensive tech. Even just 150ms from Asia to Europe would be beyond expectations.
With all due respect, that is impossible. Unless you have found a way to go over the speed of light. 15 ms gives approx. 1000 km distance. I suspect that your broker's servers are located in Europe.I have at this moment 15ms from Italy to my broker in the US. I could make a screenshot, but I am afraid to expose too much information.
Asia would have to cover double the distance, but that would still be far under 100ms.
300ms is very high. I'd recommend checking out www.ninjamobiletrader.com for a fast 1gbps and 1ms latency vps. I use their chicago vps because I mostly trade CME instruments with philips capital, but they also have NY vps which I imagine would be in the low digits ms for NYSE. Depends on where you broker's trading servers are too. For example if you're broker is based in a different city than the exchange servers, there will be more data hops and additional latency.
How would a VPS reduce latency for manual trading? It's adding another step in the process and probably even increasing latency. Your VPS could be located right next to the exchange but you still need to connect from your home to the VPS.
For automated trading it definitely the best way to go, but for manual trading i don't think so.