If you have an international user base look for a provider with a multi-redundant network connected to key Internet exchanges, tho in fairness most good data centres will be. So the other thing you can do is on the hardware side, with things like an SSD and enough RAM.
ioping on two servers, one with SSDs and the other with standard HDs (both configured in a RAID array with the same number of drives each):
1
ioping -RD -w 10 .
--- . (ext4 /dev/md2) ioping statistics ---
112.1 k requests completed in 9.48 s, 437.9 MiB read, 11.8 k iops, 46.2 MiB/s
generated 112.1 k requests in 10.0 s, 437.9 MiB, 11.2 k iops, 43.8 MiB/s
min/avg/max/mdev = 53.2 us / 84.6 us / 6.10 ms / 45.5 us
2
ioping -RD -w 10 .
--- . (ext4 /dev/md2) ioping statistics ---
11.8 k requests completed in 9.92 s, 46.1 MiB read, 1.19 k iops, 4.65 MiB/s
generated 11.8 k requests in 10.0 s, 46.1 MiB, 1.18 k iops, 4.61 MiB/s
min/avg/max/mdev = 147.7 us / 840.6 us / 163.3 ms / 2.71 ms
However standard SSDs and enough RAM is fine for most applications. What will be interesting (for me at least) is to see how they differ with a LiveView app (which I can’t wait to do! 
)