A sliding scale of "meh?"

I've been in thousands of church services. Some quite intimate in number, others amongst a crowd of thousands.

I've also lead or preached at hundreds of church services. Some with only a handful of people, others numbering a few hundred in attendance.

No matter what part I've been playing in a church service (or youth group/event), active or passive, I've departed with a variety of feelings.

At times, God has almost felt tangibly present.
At other times, I've left feeling cold and a dismal failure with the Spirit of God either completely absent, unimpressed or outright displeased.

In these feelings I'm not alone.

Everyone I know who's worked for a church as had these bipolar reflections.

But, I wonder, how dependant are they on the setting?

For, it's far easier to walk away uninspired when your church service has a dozen people and far easier to leave walking-on-a-cloud when the room is packed with people.

Is there a sliding scale of feeling "meh" about a church service or activity?

If so, how do these feelings manifest in a mega-church setting? 
Are they ever really possible?
Do you get so swept up in the largeness of what you're doing that you rarely leave cold?
If this is the case, how does this positive mindset affect you when you step into a smaller-sized service?