First impression is that it does indeed make some noticeable difference in acceleration.  It could be that its all due to just having a clean air filter.  I haven't owned this vehicle long enough to know.  But it does feel different.  Fortunately, I replaced the air filter right at fill-up.  I use this Sammy as a daily driver, and my driving route doesn't change much, so after the next fill-up, I should have some usable data.

At any rate, it is a cleanable lifetime filter.  So for less than $40 to my door, it should pay for itself in 4 or 5 cleanings, vs buying disposables.

I'll post milage data after the next fill-up.  Right now I'm getting between 21 and 23 on suburban surface roads.

Up next is a high-flow cat.  I'm just trying to get "the little engine that could" to breathe as freely as possible, both inhaling and exhaling.

Is it just an K&N that drops into the stock airbox? Or is it more of an airbox eliminator setup?

Drop-in to the standard air box.  Just like a cheap Autozone paper filter.  But cleanable and reusable, with a lifetime warranty.

Well, surprisingly my MPG actually DROPPED after installing the K&N filter.  I was getting 20-21 mpg, and on the last two fill-ups, it's down to 18-19.

But it may be due to weather changes (it's getting cold here, so I'm running more on the choke) and I think my rattling cat may finally be part of the problem.

It's going in on Monday to have the cat and headpipe replaced.  Original headpipe was 1.75", new one is 2"  I'm hoping this will help with overall breathing.

Keep us posted! I am thinking of doing the 2" also. I'd like to know how it improves...