A lot of piano VSTi’s (and other things) will post minimum specs for acceptable latency (if you can hear it, it’s definitely too much!). Does your computer match their minimum specs? If it does, maybe the interface is a suspect (and low latency drivers if installed)..?

Thing is, you’re looking at at least $1000 for anything hardware that gives even a very inexpensive (or even free!) piano VSTi a decent match. To match the results from a $300-500 VSTi, you’re looking at a $2000-3000 stage piano. A decent interface and a very powerful computer/laptop gives you that incredibly realistic piano sound for a lot less than those TOTL Stage pianos!

But that computer/interface gets you amazing drums, synths, guitars, basses, brass or anything as well. It’s what I’d go for in your position.