It depends. If you're going to use a 4G mobile connection on RUT240 and even if it has a good signal, over IPSec it's not going to be great. I did some tests that were going between RUT240 and RUT955 and the results look something like this:
With the wired ethernet connection on one (or both sides) you should get better results and I think you should be able to reach 20Mbps.
With the RUTX series devices, you should get much better performance as it uses LTE CAT 6.
NOTE: Bandwidth does not only depend on one device, but you also got to make sure that the server that responds is fast enough too.