Tuning consistency levels for your requests (R/W/N values) can only guarantee read-after-write consistency at best. It doesn't guarantee strong consistency like what HBase provides.
Mostly the limitations people come up with with Cassandra are around cross-row ACID, which if you really need it you can do with LWT, though in practice the better solution tends to be to just denormalize in to one row and/or NOT actually require cross-row ACID. It generally isn't what you really need anyway. Most businesses don't really shut down just because they can't achieve consistency.
In practice, Cassandra gets around this issue by implementing a custom CRDT for counters. But CRDTs don't exist for everything and in general it's not trivial to get things right. I'm not arguing Cassandra is bad, but it's a misconception that you can tune the consistency levels and somehow get Cassandra to behave like a strongly consistent store.