Path 1 - Shoots fast bolts of electricity into nearby bloons. The electric can bounce off the primary target and has 90% chance to hit up to 20 other bloons! This upgrade path only goes through 1 layer of bloon.
Path 2 - Fires powerful blots of electricity which can penetrate up to ten layers of a bloon. It also has a special ability: 'every bloon not popped by a shot from this turret is temporarily stunned.' In other words If you don't completely destroy the bloon in 1 shot then it is stunned and stops for 0.5 seconds. The special lasts 20 seconds and takes 1 minute to recharge.
I have added a table of what the upgrades should look something like. This is only a rough design and if you do not understand any of it then this might help:
BPP - Bloon popping power (how many layers the bullet will penetrate)
SPS - Shots Per Second
CTR (%) - Chance To Ricochet
MR - Maximum Ricochet
The Upgrade are how much the turret will increase by, for example if you purchased the turret and then upgraded path 1, once (level 1.1) then the CTR would be 35%. This is because the CTR when you purchase it is 25% and the upgrade increases it by another 10%.
The MR (Maximum Ricochet) is a little confusing to explain but i'll try my best. The MR in patth 1 awlays increases from 1 to 2 to 5 to 10 to 20. That number is the highest number that the bolt can hit (not including the attack target)/ There is an equal chance for the bolt to hit any number within the turrets MR range. The range is like this: Highest point equal upgrade total (e.g. for level 4 it would be 20) and the lowest ricochet or LR is equal to half the MR.
Some people might say that the pricing is a little high but I think that it is fine for what your getting. To fully upgrade the first path (not including purchase) will cost $13,250. This might seem expensive however path 1 fully upgraded shoots 1.5 bullets per second, has a 90% or ricocheting off, and can ricochet off to a maximum of 20 other bloons. In a just 10 seconds the TM (Tesla Monkey) would have shot 15 times. Of those 15 shots an average of 13 of those shots would have ricocheted off to an average of 15 other bloons. So, in 10 seconds the TM could pop 210 pops. Also in the 2nd upgrade path it costs $13,000 (not including purchase) which is about the same as the 1st upgrade path. This path is more about the damage. It can pop 10 layers to a bloon and can shoot 0.75 times a second, the range on this is double the first upgrade path. In 10 seconds this path can pop 100 bloons, which seems terrible considering the other path can pop more than double. However this path can slow down enemies and can take on stronger enemies a lot easier that the other path.