My case is WP+5 years (Set (O)). I am a university lecturer. I am with the same university under single WP for the last 5 years. I applied premium ILR at Birmingham PEO yesterday (12/02/2010). Previously the appointment was on 16th Feb at 10:30 AM. I previously booked flight to travel to PEO on 15th, overnight stay at a hotel and return on 16th. As the date was changed for the same 10:30 AM appointment, I called them to give me an appointment some time later on 12th itself. I got a reply that any time before 2:00 PM is OK. If I need to change the date then I have to cancel this one and start booking again. Who wants that pain
I paid extra £218 for the flight amendment 
and cancelled the hotel reservation.I entered the PEO at 10:13 and after security check I received the token at 10:16. There was problem in finding my name in the appointment list. The name in the list was with my wife’s first name and my first name together as a single full name. Finally last 3 digits from my mobile number solved the issue. They confirmed whether the first name in the list belongs to any other dependent. I told yes it is my wife’s first name. I had to wait until 11:05 for the call. Then a friendly case worker handled my case. He said he will go through everything one by one starting with application and passports (myself + 3 dependents). While looking into the application he saw extra page added for absences in the UK. He asked me totally how many days I was outside UK. I answered 400+ days. I mentioned clearly that except 3 visits (total 96 days) all other visits are related to research and conferences. I have also mentioned the name of the sponsors for the trips. He said he cannot make any decision and he has to check with his supervisor. He asked whether I have support letter from the employer for these absences. I said yes. He then asked for our marriage certificate and two birth certificates. He also asked me the ages of the kids. He confirmed with me about the UK birth place for both kids. He then checked with me how recent was the photos taken. He collected Life in the UK test certificates. He then asked the employer's support letter and 3 months’ salary slips. He read the whole letter which ran for two pages. In the letter all the absences were clearly mentioned with the purposes and sponsors for each visit. It has also been mentioned that for the complete 5 years period the salaries were paid in the UK, taxes and NI contributions were paid here. He then excused me to meet his supervisor. He was away for nearly 10 minutes. I think the senior case worker was busy with some other case(s). I saw my case working crossing few times here and there inside. Then finally he caught his supervisor in front of my booth only. They had very brief discussion and then my case worker approached me to inform that they are happy to give us the settlement. He did not ask for any further document from me. Not even WP or P60 or bank statements. He was so kind to mention that he can see all those records in his screen itself. He then quickly went through the screen and asked whether we once applied for visa for our first kid in the UK. I said yes we applied by post before going to India for vacation in 2005 and it was not processed as they returned the application as an obsolete one. Later we went without a UK visa for the baby to India and applied in India. He asked whether home office refunded the application fee here. I told him that they did not even charge a fee here for that application. I also told him then the application fee was very less in India compared to here and later everywhere it has been standardised. He acknowledged that. I mention this point as they can see in front of the screen what all the applicants have done with the home office. He then asked me how I reached Birmingham. I told by flight and extra money paid for amendment due to advancement of appointment. He apologised for that. He mentioned that for 3 days no appoints were booked. For other 3 days double appointments were booked. So they had to rearrange them. He discussed for sometime about my research and related things. He has good idea about my research work. He is a very friendly & kind person to discuss many things while he was checking all the documents. He finally said it may take good 2 two hours time before they call me and gave option to go out for lunch or something. I thanked him and then went to pay £1170. When I finished that it was 11:50 AM.
There was no separate document checking before meeting the case worker. I was called by the case worker directly after I got the token and paid the money just after the approval for ILR issuance. I went out for lunch in a Chinese restaurant located opposite to PEO. I came back to PEO after 1 hour and 40 minutes. I was called within 10 minutes and asked to check the spelling of the names and DOBs in all ILR stamps. All OK and I thanked that person and came out. At that time it was 2 hours totally after I paid the money. So it was pretty quick compared to other recent cases I read here in the forum.
There was no need for any consent letter or authorisation letter from my wife. Personally I feel only the main applicant is applying all others are dependents added within that single application. So in principle there is no need for any letter from the dependent for not appearing in person.