To what degree should the oldness of my phone affect my tethering speed? I have an iPhone 4s on Verizon that I am using to tether with Bluetooth. TestMy.net indicated a throughput of about 200kbps, which it suggests is 2% of the typical throughput it sees from Verizon.

It occurs to me just now that it could be comparing this to FiOS speed instead of other tethered network clients, but my question is: would I expect to see radically different connection speeds if I was using an iPhone 5s instead of the 4s? Is Bluetooth less capable than wi-fi tethering?
Bluetooth is slower than WiFi but it conserves battery power.

BT are capable up to 2 Mbps, which equals 240 KB/s, sounds like you are right on the target.

Kilobytes per second (KBps) and Megabits per second (Mbps)

Source:


  Bluetooth 2.1+EDR, the flavor built into all iOS devices, has a raw
  rate of 3 Mbps and a net throughput that’s just a bit over 2 Mbps.
  That’s fine on Verizon’s 3G network, where average speeds never top 2
  Mbps.