Well I've had Flow for a while now, and over that time I've found a few fundamental flaws.
1. It's too well balanced! The centre of mass is right between the wheels, which gives awesome grip and amazingly well handling drive, but it wheelies far too much. I added an HDPE skid for the UK champs, and it worked perfectly to keep the front firmly on the ground. One problem was that it broke, leaving the robot as wheelie prone as before.
2. Front is far too steep. As can be seen from Flows performance in 2012, the front end is too steep to wedge under other robots with ease. I fixed this for the champs with a lip bolted on made of some jet turbine titanium the Nipper boys use on their robots. When it was new, it worked nicely with the skid to give ultimate wedge-ness! If the flipper was going it would have done better I'm sure. Problem is, it eventually bent up, and became unusable.
3. The shell just isn't up to it. Flow took tons of damage at the champs. All cosmetic, but damage nonetheless. Pretty sure it's now written off and unusable. So, new shell for next year.

I have a nice list of changes to be made:
Swapping 10bar valve for custom full pressure valve
New shell: 8mm welded HDPE, front end 20mm, with a small 3.2mm Hardox frame around the base to ward off spinners.
Sturdier skid.
New 3.2mm Hardox lip.
TX mods to help with flipper activation.
Possibly smaller capacity Lipo for comp. fights, new bulkheads and if weight allows some 2mm gr5 ti bottle protection.

Another thing I want to do is change the drive from TWR15s to Astroflight 940s with TWA40 gearboxes giving a very slightly higher top speed but heaps more torque. But the liklihood of me being able to afford that is minimal :P