[Michael Peterson]

I'm up for a wider sill brush, better for using the aqua tap

[Dave Willis]

I have an Xtreme dual trim mixed medium that's been trimmed so that the inner and outer bristles are the same length.
It feels better than the standard brush to me. It's a shame the bristles don't behave the same when they are wet. A dry brush feels perfect but goes floppy when wet.

Having said that I don't think there is a huge difference between any brush - they all do much the same but it's the weight that makes a good or bad brush.

[robbo333]

A wider sill brush...about another 50mm. That will make it feel quicker over the glass but any more than that, could make it feel a bit cumbersome. And if you could keep the weight to a minimum. Can you make the brushes from carbon fibre rather than plastic? When the brush gets worn, could you offer a bristle replacement service?
OK...sorry i'll stop.
Thanks Alex

[CleanClear]

There are four rows of bristles on an Xtreme, a fifth, central row would be interesting. Maybe even just slightly shorter than the inner two rows- the worlds first "triple trim" wfp brush!!

Think it already exists. Is this what you mean....

http://www.windowcleaningwarehouse.co.uk/SKU4710.html

Although that looks a fine brush Stephen, i think you'll find the large stock on the brush leaves it at a weight disadvatage when compared with a lightweight slim stock brush ?