Megapulser is size 3, +8 charge
Gigapulser is size 5, +10 charge

Most of the items in the game scale better as they get bigger. In this case, the Harmonic Gigapulser (which comes off of a harder boss) takes up proportionately much more space than it's lower level cousin.

Is this what how the item was intended to be or should it be more like size 5, +14 charge?

Some special items (like these) scale differently than standard modules.

You're talking about an increase in 2 seconds. Doesn't sound like much, but compound that over months and months of gameplay... 2 more deck spaces?? No problem. I'll take four please.

~ D

As Drake alluded to above, you can have four of them. So that quadruples their benefit. -8 seconds per tick soon adds up.

I currently have a recharge rate of 1934 shields per hour. I have 3 GigaPulsers and a MegaPulser. If I uninstall them, my recharge drops to 1234. So they're worth it, trust me.