Actually I thought that some tuners took the modified value and other tuners used the unmodified value. I could be remembering wrong though, has been awhile since I looked into it.

Agree with stacking penalty in concept

But NERFING is too in fashion these days and doing this requires thoughtful balancing.

This game is in desperate need of adding more bots, mods and features. The discussion on nerfing this and nerfing that is getting depressing.

Yes that's true even when we start introducing new bots with 10 head slots its going to become a really big problem.

This is the reasoning I could find for Eve's stacking penalty implementation:

There was originally no stacking penalty. This caused all manners of havoc with players equipping many modules of the same type. Ships with many low slots would wield many damage enhancing modules for firepower that could instantly vaporize almost anything.

+1

Less multiaccounting and you'll see the worth of your "90% useless modules".

+1

True Pros make a Podcast to influence the Devs minds, 
The rest of you guys are Hacks

PS. I got my Highways & stopped playing b4 they came in & have never used them! ...... Irony much ?

Dazamin which faction you coming back too?

Formulas

That's the whole point of stacking penalties. Like 'let see, this tuner only gives me 2% more damage, therefore not worth fitting, so leave slot  empty for speed or add one of these 'useless' module.'?

i dont think we need to nerf tuners.

it can only be used in great numbers in pve. in pvp i havent seen much bot with pure tuner fittings yet. most likely because they lack range and are too vunrable in other terms. (and i havent seen a lot SR fleets in the past)
and i think for pve its ok to power up a bot a bit...

if you give the tuner a dimishing return buff then they will become useless after two or three mods. this will limit the fitting diverity. so im pretty much against it.

if you want to remove the exponential increasement and do for a linear aproach then the solution lies in the math:
the tuners are stacking exponential because they have multible stats (dmg, rof, and cirt). each of them add multipicatively. and if you boost 3 stats multiplicativly then you have a expnential increasement.
one solution might be to reduce the bonus only to one stat (for examle dmg), but of cource a bit more of it because you remove the other two. then you will get a linear increasement for every module you add (if you get your math right).

but personaly i dont think its nessessary to nerv tunings. i think powering up dmg is ok. your other options that you loose are:
range
sensor boosting (if you dont have rsa)
ewar resistance
rep bonus
...

on the other hand a few other modules could use a boost. like the armor repair tuning that was nerved to death multible times.

I like this, as the same will be applied to extenders as well.  As well as every other mod in the game.  Really shaking up the basic foundations of PVP, and the normal fits.

It would effect PVE, but that doesn't stop you from putting all tuners in the head.

+1  Hope this happens when steam comes out.