Since I'm an audiophile, I'd rather have the V30, because it has a very good dac/amp. It's also got a (subjectively) better design, and it's also waterproof, unlike the 5T.
I have a Oneplus 5 currently, and I love it. The 5T is a very good phone for the price, but if you want the extra features of the LG, then I'd say go for that one.