My case:
WP+WP+T1.
Absences from UK 235 days (incl holidays, weekends, annual leave, business trips but all were paid)
I arrived with family about an hour before appointment after long long drive on miserable rainy day. 2nd Security guard was cooperative and allowed shelter

Case worker was very helpful. She went through all documents mentioned while validating my form earlier, had a glance on absence spreadsheet which contained details of entry, exit and number of working days excluding weekends (150 in mycase), said I was ok with number of days out. She also revailed I had scored brownie points over my wife in LIUK. happy me. She took copies of my documents and told to collect passports after 1.5 hours.
I came back to collect my passports with 'stamp of independence' from visa hassles. All process went extremely smooth.
Lessons learned:
- Call HO to check if family is required at appointment, this saves lots of hassle especially with kids.
- Check nearest PEO office and then take appointment, ensure you avoid traffic hotspots like M25 if possible
- Write case reference number, one sent by SMS, on top of application.
- NCP car parks, ensure you go out in 15 minutes from payment timestamp. 16th minute and you pay..I always believed parking is best business.

cheers!