That is the question.

Just curious. I want Invulnerability on my weather controller. I don't particularly like playing glass canons. With that in mind I had long ago created a build that utilized various energy form powers for a full GB charge. With Field Surge no longer being able to do this it makes it a bit more difficult.

Anywayz, I was thinking that I generally tend to spam GB, energy form or not as it feels quicker. I did a little math to see the difference.

Tap: .67 sec
Charge: 2.33 sec

2.33 / .67 = 3.4776

Tap: 348 damage
Charge: 1487 damage

348 * 3.4776 = 1210 equivalent Tap damage.

Now take into account the extra arcing effects

79 * 3.4776 = 275 damage

Tap: 1210 + 275 = 1485
Charge: 1487 + 79 = 1566

There's only difference of 81 damage between the two. If you do a little more math you'll see that there's only an 8 energy difference between them as well.

Tap: 40 * 3.4776 = 139
Charge = 131

Basically is it worth it to use up so many slots just to be able to charge GB when there's really not a whole lot of difference between Tap and Charge?

EDIT: For the record here are the powers I would use to gain Energy Form.
Force Bolts (Energy Refraction)
Electric Sheath
Circle of Arcane Power

You forgot to account for the activation time when comparing tap vs charge. A full charged Gigabolt takes 3 seconds, 0.67 activation + 2.33 charge.

Tap: 348 / 0.67 sec = ~519.4 dps
Charge: 1487 / 3 sec = ~495.7 dps

Tap spam of powers usually yields higher dps, but is less efficient. Gigabolt is no exception.

Taking that into account

Tap: .67 sec
Charge: 2.33 +.67 = 3 sec

3 / .67 = 4.4776

Tap: 348 damage
Charge: 1487 damage

348 * 4.4776 = 1558 equivalent Tap damage.

Now take into account the extra arcing effects

79 * 4.4776 = 354 damage

Tap: 1558 + 354= 19117
Charge: 1487 + 79 = 1566

There's only difference of 81 damage between the two. If you do a little more math you'll see that there's only an 8 energy difference between them as well.

Tap: 40 * 4.4776 = 179
Charge = 131

So now there is a significant difference. Tap dealing more damage but costing 48 extra energy. That's more or less what I was expecting. However, Arella is built for energy gain so I think I'm going to go the Tap route. :D

There are tactical implications as well for the difference of tapping or charging.

Charging gives a high First Strike damage. Against henchmen, a charged Giga is often all you need to end the fight. Against the rest, the mobs are more dmgd when they return fire.

The downside to this is losing the energy form for a few seconds.

Now consider this scenario. There is a lot of blocking terrain. The enemy is visible/hidden by the terrain
on a regular basis. In this case, tapping works better, as the enemy may have become hidden by the time the bolt is fully charged...

Or this scenario. Youre facing a tough boss, legendary/cosmic, etc. You want to block his attacks.
Tapping may be all you have time for before you need to block the next attack.

In the end, i went from charged Giga, to tap only Giga, to no Giga at all in my pet build, as i found that the build was power starved... Every power not chosen means yet another pet...

Well as far as that's concerned I still have Circle of Arcane Power or Electric Sheath. I think this is most likely what I'll do, Charge initially and then tap during fights. The main role of my hero is actually AoE damage goodness. Gigabolt interferes with her Lightning Storm maintain. It'll be more of an addition than a staple.

STR/INT Defiance Enrage Gigabolt is pretty easy to play, and has the added bonus of absolutely launching things with Sparkstorm.

Was thinking about going END/REC Invulnerability. Using Ionic Reverbation, Force Shield, and Circle of Arcane Power for even more energy madness. Here's the build I was planning:

Build by championBuilder 0.4.1

Arella: Level 40 Champion

Superstats:
Level 6: Super Recovery
Level 13: Super Endurance

Powers:
Level 1: Electric Bolt -- Lightning Overload, Ionic Infusion
Level 1: Ionic Reverberation
Level 6: Sparkstorm -- Rank 2, Electric Personality
Level 6: Flight -- Rank 3, Rank 2
Level 8: Invulnerability -- Rank 3, Rank 2
Level 11: Sigils Of The Primal Storm -- Rank 3, Rank 2
Level 14: Force Shield -- Force Sheath
Level 17: Heat Wave -- Engulfing Flames, Rank 2
Level 20: Invocation Of Storm Calling -- Rank 3, Rank 2
Level 23: Circle Of Arcane Power
Level 26: Gigabolt -- Rank 3, Rank 2
Level 29: Lightning Storm -- Rank 3, Rank 2
Level 32: Electric Sheath -- Rank 2
Level 35: Vapor Form
Level 35: Teleport
Level 38: Rebirth

Talents:
Level 1: Energized
Level 6: Tireless
Level 9: Energetic
Level 12: Agile
Level 15: Amazing Stamina
Level 18: Impresario
Level 21: Accurate

The thing that tapping gains is that you have more chances to proc Ionic Reverbration from it too.

I usually find that I can tap-spam down a villain, and may or may not manage it on master villains/super villains depending on the RNG.

I leveled one character from 26 to 40 with Gigabolt as one attack, and my only option to charge it was to use my offensive break-free click, so tapping it is indeed a viable approach. In my mind the value of the electric form is not so much charging GBolt as it is the damage increase, although it is nice to use a charged GBolt as an alpha. If you are running Invulnerability, alpha-striking is less important.

As to the build, will you really use that many AoE's (Sigils, Invocation, Sparkstorm, Lightning Storm and Gigabolt)? I might drop one for a self heal like BS or Conviction and take a bit of PRE on gear/talents.

Its also worth noting that during the cooldown on a charged gigabolt, you can't use Electric Sheath at all. Meaning no emergency breakfree+shield+damage boost+energy efficiency spike. That you might, you know, Gigabolt out of for uber damage (After, I suppose, Lightning Storm to slam them to the ground a couple times, since there's no point stripping off sheath immediately)