Yes as you mentioned, no noticeable differences.
How the test was done:
user@host:~$ sudo virsh edit Whonix-Gateway
At the bottom of the file add <rate bytes='1024' period='1000'/>
similar to:
<rng model='virtio'>
<rate bytes='1024' period='1000'/>
<backend model='random'>/dev/random</backend>
<address type='pci' domain='0x0000' bus='0x06' slot='0x00' function='0x0'/>
</rng>
</devices>
</domain>
Then start the VM. (repeat the same thing with Whonix-Workstation)