[Greg Reid]

I''ve only been doing this for a couple of years off and on myself so take this with a grain of salt..but...You're not gonna magically start welding solid beads if you can't now just by switching to gas if that's what you mean.
On the other hand, yes, there is quite a lot of difference in the appearance of the welds. The gas will require less cleanup and the welds will be generally prettier..
Get good at the flux core by practicing a lot then switch to the gas setup and you'll feel like a pro.
Personally, I had no problems doing some practice welds with the flux wire...Just had to do quite a bit of grinding to smooth them out.