Delisted.com = zero value and zero chance of anything in the...

Delisted.com = zero value and zero chance of anything in the future, but you can take the capital loss now.

Keep private shares = small hope one day the company might pay a dividend, or buy your shares back, or relist on a stock exchange. If they continue operating then they will be worth something, just harder to value and even harder to realise that value.

I personally won't be selling them to delisted.com until I actually have a capital gain that I need to offset, and I'm sure nothing will ever eventuate in terms of future value.