Finally got visas through.
6 May to 5 Jan - so 1 day short of 8 months in total.
It's worth mentioning that my solicitor returned from Xmas break and there had been no visas issued from INZ (after 3 weeks). They called INZ and the person they spoke to said there wasn't any record of the passports being processed/scanned in the UK. I called VFS Global in London and got the passport processing reference numbers (they confirmed the passports had definitely been processed correctly) my solicitor then forwarded the reference numbers onto the CO, within a day we had the visas issued. So not sure what happened with that, but just a note to others that you can get those reference numbers and get back in touch with your CO if the visas don't get issued.
It really is so difficult waiting for such a long time without any input or responses, but hang in there all those still waiting, it's worth it when the visa finally arrives!