Hi lovemygreen,
I think it depends on what you're looking to do with your lawn. The standard 6 blade reel will do a very nice job if the bedknife and reel are sharp and properly adjusted. Usually you would increase the number of blades if you plan to mow very low - If you're after a putting green for example, I think you'd see some benefits. Otherwise the increased number of blades can cause a fanning effect and actually reduce the quality of cut.
I've been experimenting with it myself, I have a 10 blade in my Rover 45 and a 6 blade in my Scott Bonnar and at very low heights the 10 blade is great. I use the 10 blade on my back lawn and keep it very low and use the 6 blade out the front at a more conventional height. Both cut beautifully. The downside to mowing very low is the increase in maintenance. I try and mow the backyard daily and at a minimum 5 days per week. I also keep a maintenance schedule for watering and fertilising.
There's some good info
here if you're interested to read a little more on how the frequency of cut works.
Michael
