In reply to Tyler:
I whole heartedly recommend Croesor to Rhosydd Through Trip ("CRTT"). In the past there has been an element on the forums "too dangerous" "irresponsible". But if I suggested a mountain scramble route which is arguably more dangerous nobody says anything. We're grown ups.
Yes there are some sections of CRTT where extra care is needed (minimising time and moving gently in the first big cavern). Pulling up inspecting fixed abseil ropes before use, checking anchors, safeguarding abseils in some manner (like prussic third hand, grigri, stop, shunt, fireman belay etc etc). But this is basic basic stuff.
If the OP of this thread has a strong sense of adventure, can jumar up sections of rope if needed (and takes means to do so!), takes a spare/emergency rope of their own 50m @9mm should do it), has a helmet and head torch with 5 hours battery (and spare batteries for another 5 + emergency torch), has some lanyards/cows tail tied to harness then in my opinion anyway the route is an excellent mini taster/introduction to a whole world of big-cohones adventure.
If people are sensible and can look after themselves on a mountainside, can ascend rope then why the heck not do CRTT??
HUMBUG!!! To the bah humbug brigade, I can take your down votes.
Go for it OP, you will have a great adventure. Go and paddle a canoe underground and all the rest of the "fun". No you don't need to take lots of specialist pulleys, if you read any of that in instructions it's out of date
Edit: happy to provide links to instructions, where to park and any other advice or info
Edit2: https://imgur.com/a/KjFzmGS survival is possible
Post edited at 12:15