I've been decorating cakes for about 5 years and I've used cake mixes or the 3D durable cake recipe. I love the taste and texture and it holds up the fondant really well.  I'm wondering about sponge cakes - are they dry, do they hold up well under fondant, etc.  I've never made a sponge cake before  I've made pound cakes though.  I'm wondering about what kind of cake to use for my cakes.  I don't knowing I should stick with what works or try something new.  Most of my cakes are either one or two tiers.  All information and opinions would be appreciated.  Thanks  

I'm a hobby baker and also use Duncan Hines cake mix as my dry starter base, then I add a bunch of stuff to that dry base.  (Most recipes adapted from Anne Byrn's Cake Mix Doctor.)

If people like your cakes and they are consistent, stick with what you know.  Sure, there are about 2 million recipes out there, but I've also been hobby baking since 2010 and don't want to fix something that isn't broken.

That's true.  Everybody that has tried my cakes absolutely love my marble cake which is Duncan Hines doctored up with sour cream and pudding.  It is moist and holds up well to fondant.  I tried a few other marble recipes but found them all to be dry.  Maybe I should just stick with what works for me.