CP Saw is actually very good as a hero, and was so much better when he still had his decaying slow on B instead of slow only while hit with the ability. I think CP Saw is actually the reason they removed it, since you could easily chase down enemies with the A or push in with your C on full speed, unless it is just a lasting unintentional bug.
He has a great poke with his B that if you time it right, can prevent many ranged heroes early game from getting close to you or pick off running enenies from afar, while doing considerable damage, and late game it can put the hurting on them from afar, enough to deter them. His A is one of the best abilities in the game. It’s free boots if you don’t hit anyone, and a free unengage if you do. You can use it to fake enemies out and make them run away, just to line them up for a B and C combo, not to mention you get another one if you can complete your B? As for mad cannon, it is somewhat lacking early game, but as CP Saw it’s just a finisher early.
Late game is when his mad cannon comes into play, as when you have 9 bullets loaded and another C ready, you can combo your abilities to kill multiple enemies easily. I’ve taken down 3-4 enemies solo just by timing my abilities right and having 18 bullets of mad cannon ready and a slumbering husk plus eve on me. It really kicks off if you have a DE, as you can get about 4 stacks out of a full B by itself ( you only need about 6-7 to equal an SG) and build the rest by AA with lifesteal dealing with any damage you take.
As @NerfElfPls said, if your stutter stepping and positioning is good with cp saw there aren’t a lot of enemies that can take you down fast enough, especially solo. Best part is cp saw can be played in any lane effectively, and he doesn’t have as much weakness to stuns as you might think due to his range dmg and ability to run every 5-6 seconds. Not to mention the best part of all: your knife still can hit and roll away if you still have run time left on it after you’ve been stunned, saving you from a lot of near death stun combos.
WP Saw, on the other hand, is pretty much useless without a teamate by late game. If they gave Saw his AA range back it wouldn’t be so bad but WP Saw has no approach or deterring power late game and it makes him pointless for anything other than objective stealing, which is pretty much all you should be doing as WP Saw anyway.
This is coming from a CP Saw main since near when I started playing. He is truly one of the best and safest heroes to play if you know how to place your cams and time your abilities from the appropriate distance.