What buffer setting are you using?
We sometimes track at 256. There is some delay although that can work if you stretch your ears a bit. 
We did use an RME Fireface at 64 samples which was barely noticeable.
For live work I have used a combination of Cubase and Focusrite monitoring - Running the main sound latency-free and simultaneously routing the signal through Cubase, adding delay, flanging, reverb. Just makes the sound bigger.
Personally I am not a fan of adding vocal effects live because they make it hard to get a good resonance.
Hope this is useful. Good luck,