The singer returned to the complete the original line up of the group last year, and their live return came together last week with their opening of their Progress Live 2011 Tour.
The four dates of the show in Sunderland, Northern England, finished on Tuesday (31.05.11) and Robbie is elated at how things have gone so far.
In a post on robbiewilliams.com he wrote: "Sunderland you've been awesome... the last night of the 4 was my personal favourite... In fact the most fun I've ever had on stage. Me and the lads are made up with how well everything's being received we feel the love thank you thanky you thank you right (sic)!"
The group ' which also includes Jason Orange, Howard Donald, Gary Barlow and Mark Owen - will start the next leg of the tour in Manchester tomorrow (03.06.11).
Meanwhile, Robbie said he and Gary are working on material for a new album, comparing their relationship to that of Beatles songwriters John Lennon and Paul McCartney.
He said: "Garry is great for me because he knows how I should sound. He wanted to make a Lennon and McCartney-type album. That was his big idea - big, standard records.'
'At the minute it's just me and him finishing the album and I love it. Love my friendship with him. Love that he regards me as an equal.
"Gary is kind of unemotional about stuff. I'm emotional about stuff. He's solid. I'm fickle. He gets stuff done, I don't.'