I know that it's strongly recommended that you keep the client version sync'd up with the server version, but there are a LOT of breaking changes when generating queries that used filters in 1.7 in 2.3. We're working on rewriting those, but we also don't want to delay our upgrade on the server-side significantly as we work through that rewrite and testing.
Should a 1.7.1 Java client work ok against a 2.3.2 server? Are the filters are still supported for backwards compatibility but deprecated, to be removed in 5.0?
My initial testing has not gone well, as I can't even seem to get a connection (getting NoNodeAvailableException), but that may be more networking related.