From what I read, these reels are meant to make very long casts with specific weights.  Is it fair to say than if the weight is too light or you dont make an aggressive bombing cast, the reel will backlash or will it just not cast far?

Backlash.  These are wild reels.  You should also avoid stiff line like big diameter flouro and mono.  People who try to use them as a normal reel don't like them.  They are a niche reel for long casting.  

I have one, it's an awesome reel when used as it's intended but doesn't offer much braking for light baits and light casts. I ended up putting a different spool in mine for everyday use.

Where would it be a good fit?  

I have 2 HLC Zillions. I'm not sure of the braking profile of those compared to Steez. I don't use them for throwing finesse type stuff but have absolutely no problem throwing 1/4oz. anything. I can bomb 1/2oz. Lipless, drop down to a 1.5 size Squarebill or a 5" weightless Stickbait without a hitch, might have to go a click or 2 up on the dial, but zero issues with 14lb Fluoro. Brian. 

1 hour ago, Jeffrey Walker said:

Where would it be a good fit?  

Braid with frogs in a high ratio.  Deep cranks in a slow ratio.  Weight transfer hard baits like jerkbaits.  Compact 1/2 oz and up baits.  Rigs with heavy weights like heavier Carolina, 3/4 oz football jigs, bigger biffle bugs if that's still a thing.  Just don't try to run 20 lbs flouro through it.  

For me the key is a harder cast, especially with lighter baits. The inductor springs are pretty stiff so it takes a decent amount of force to get them to activate. Anything aerodynamic that you cast fairly forcefully will work. You can also get a 36mm spool from the OG Zillion and use the reel for anything.