Is this new or am I just late to the party ??

That size makes sense for a 40-50 degree bag. Lots of makers are hitting that size. Weight does seem to vary a bit, depending on what fill is used. You can find down quilts or bags that pack down that small as well but go quite a bit deeper into the cold range.

I haven't used that particular Marmot, but I've used other ones and been very satisfied with their products. You are bound to get a variety of opinions on bags though. This one would probably work well for late Spring, Summer, so long as not at higher altitude.

It's EN comfort rated to 56 degF. We're not talking about a very warm bag. You'd probably be even more amazed how small a 50-degree down bag will compress down to.

Saving weight is awesome, simultaneously saving pack space is bliss. If you are looking at warmer month hiking in FL, a bag like that will probably do you pretty well. Obviously look at bag size to be sure of a good fit.

No offense but that is just a generic synthetic bag with a bunch of gimmick words thrown in. I'd be waiting till spring and grabbing a down bag on sale. Marmot in general make good products. However, this bag is nothing special. The only thing good is that at least it is EN-Rated.

For comparison, I have a +40F Golite Featherlite Down bag that weighs 1 lb, 4 oz and stuffs down to a grapefruit easily. There is nothing on the market that compares to Down. I paid $125 for mine. I use mine year round in temps down to 0F with clothing supplement. 

Let's start over.

What temperature range are you planning to use this bag in?
Do you care whether it's down or synthetic?
Is the 6' length the right length for you?
Do you care that it's a sleeping bag as opposed to a quilt?  You can save weight on a quilt because you really don't need a hood at those temperature ranges.

I think the bag you linked to was $79 -- so is your price point around $100, or less, or...?

Just for comparison, a "good" synthetic 40deg quilt will cost about twice that amount (~$150) but will weigh less than a pound (the Marmot sleeping bag you linked to weighs 1lb 13oz.)  "Good", in general, means accurately rated for temperature, well-constructed and better warmth-to-weight ratio.

+40F means it is 40 Fahrenheit (above freezing) as compared to my setup that takes me to -60F. If weight/space savings is preferred, Down will win every time, by a significant amount. $100 as a budget is tight but doable in the temp range. However, most bags will probably be 550 - 650 fill (more percentage of feathers). I would shoot for the 650 fill bags obviously. The loft in a down bag will outlast a synthetic by many years.