A version of LOR and SITC were exploitable.
With the exception of progressives, bonus banking, accumulating, must hit, most slots are and never were exploitable themselves.
All slots have the potential of being exploited with casino promotions and mail.
It may not be as good as it used to be, but it's not even as close to as bad as some people think/claim, it's just different. For example: back in the day, there was no such thing as free play. Nowadays, almost all casinos offer free play.
I haven't really gotten into the new machine sniping game, so I cant tell you how good it is. You can ask 20 different people and they will all have a different answer.
I can't imagine its as good as it was back in the 90's but I could be wrong. Not to mention there was nowhere near the amount of hustlers like there is nowadays.