REDIS tradeoffs have been so widely discussed because many, many engineers disagree with them. REDIS is so lowly regarded that some companies ban it completely, making their engineers choose between memcached or something more enterprisey (hazelcast these days, Coherence some time ago).
The source code is magnificent.
Why are you writing Redis in all caps like it's an acronym? Reminds me of those old dog C programmers who write long rants about RUST with inaccuracies that belie the fact they've never actually used it.
Core Redis is a solid piece of technology, afaik
Distributed systems is hard, and what seems like a trivial choice about design constraints can quickly balloon in cost. =3
I have a dedicated server that's running an instance of redis on each of the 32 cores and it's been up for over a year now. Each core is doing about 30k QPS