One of the differences is that the sliding in this phone is flat, unlike the upward angled in the N97 mini, hence allowing a four row QWERTY keypad, bringing a slightly enhanced typing experience to the table.
The Nokia C6-01 is the successor to the C6-00 featuring a major step-up with the new Symbian^3 operating system, Ovi Maps 3.0 and such but losing the QWERTY keyboard.
Cnet UK wrote that 'The C6 suffers from the worst excesses of the N97's software, without the saving grace of its solid hardware, resulting in a phone that's disappointing at any price.
[5] T3 magazine said that 'This is a decent phone, but unlikely to convert anyone to Symbian, making it a handset for Nokia fans, with the priority of texting and emailing'.
[6] while techradar.com gave it three out of five stars and stated that while the phone had useful widgets and a nice screen that those features were countered by general usability frustrations.