An IMCR substantially expands your ability to do VFR flights abroad, because you can fly and navigate in lower vis, fly and navigate above an overcast, and you can penetrate IMC if this is necessary. In an emergency situation you can fly an IAP also, because you know how.
It makes you a much more confident pilot. Almost no really long VFR trip is possible as 100% totally clear of any cloud whatsoever. Well, it is possible if you are a permanent retired pilot with plenty of time
I would still be really careful to avoid ending up looking like a d1ck at the destination, because if the wx is OVC002 and you call up "VFR inbound" at 5000ft overhead, it is kind of obvious.... but enroute is a different thing.
The IMCR will not help you with a departure from a non-UK towered airport because they have VMC/VFR minima e.g. 1500ft cloudbase so if it is BKN009 you are stuck there no matter what. That actually happens quite often to VFR pilots.
"In sight of surface" is unenforceable and meaningless - assuming you are technically capable.
BTW the IMCR allows IFR in Class D,E,F,G in UK airspace, not just Class F,G.