What are your thoughts about it? Is it harder or easier to care for? Do You need to test/change water more frequently? Is it necessary for the bacterial flora to have gravel? Give me your pros and cons about it.

I was thinking of chucking the "fluorescent disco"gravel (my hubs dubbed them that-says they're hideous ) that came with the kit. Then maybe opt for a few smooth natural river rocks and maybe a terra cotta pot with some plants or maybe a glass tube submerged with some natural stones plus plantings.

It may be easier to clean a bare bottom tank, but as Kat mentioned it is everybodys preference.
I prefer to have some natural looking gravel, plants and some deco, airstone andanother small bubbler.
It gives our fishies sth to do, as they are busy all day, digging, sucking the gravel and re scape. It is their nature, LOL 
... and the gravel hides the poop...

well I have glass stones in the bottom of my tank, they're alright but again, kinda hard to plant real plants. I have one in there now, and its doin alright cause I have it lightly covered. personal preference

I would totally NOT go with bare bottom. Because I appreciate a more natural look to the tank. And gravel ain't that hard to clean with a siphon d: You just do it during the water changes.
Real gravel also allows your goldfish to stick to their natural behavior, they are picking up gravel in their mouths, and spit it out again in the search for food. That's why you should choose a rather smooth gravel so they won't hurt themselves on it.
Plants need to be planted in gravel, rather some finer kind to thrive. You can't simply plant them between pebbles on naked bottom, so you'd HAVE to use plastic plants in the tank, which may make it look rather sterile. And the goldfish love snacking on real plants ;> And the plants absorb nitrates from the water, and that's a really good thing
BUT, I won't lie to you, it IS a really good place for dirt and bacteria to be collected. That's why it's important to clean it regularly, and to test your water. (which you should do anyway)

You should totally do that! It can't be emphasized enough! xD (People still won't get it.)

PUNCH HER IN THE TEETH! GRRRR!!! I HAS AN ANGRY! MINDE I HAS AN ANGRY!

Well, her reply always is when I try to explain how she could have a nicer looking tank is : "They're fine! Quit bugging me about them!"  But when she comes to my house she always comments on how nice my tanks look and has said "Gee, why don't you come over and fix my tanks like that."  But when I do come over she won't listen to what I have to say!  GRRRR...frustrating? Yeah! to say the least!

Then one time she had this lights up chicago skyline thing in the tank with nothing else because it was so huge for a 14 gallon tank.  Her fish didn't even have swimming room!  I told her it was too big for her tank and so finally she took it out when I finally told her it looked dum.LOL!  
I just think she is one of those people who think fish are a lesser pet than a dog or cat and if it dies "oh well" it's replaceable and have that attitude.  And it irritates me!!!!

i hate people like that. no respect for anything. makes me want to PUNCH THEM IN THE TEETH!!!

Gosh girls, can you see the smoke out there in the sky? I AM FUMING !!!! It makes me WILD, ANGRY, FURIOUS, I HAVE ICICLES IN MY EYES when I experience people like this: asking for advice, but then completely ignoring it, treating others including their pets like rubbish, don't know what they're talking about as if they are brain amputated... GRRRRRRRRRR, BAAAAH, KICK, CRUNCH

 

oh I know, Yubonne!  One time I was out of town shopping for a new fish and these tanks at Pet Supplies Plus had dead fish in them.  So I told the girl and also told her that I wouldn't buy any fish while there was dead fish in a tank.  She just said Ok.  Well when I went to get my stuff I needed I checked to see if she had taken the dead fish out!  IT WAS STILL THERE!!  Ok, I was fuming!  I went and found a manager and told them.
The next day i happened to go back in the store and the poor dead fish was still in there!  So when I checked out I told the girl at the checkout and I'm afraid gave her a bit of my mind, since this store promotes animal well being and adoption.  She said I'll go take care of it right now!  And she did!  I mean how long does it take to fish out a dead fish out of a tank? less than 5 mins? 

YAY! PUNCHING PARTY!!

No, seriously, when I went to get my tank I saw a little common goldie floating about dead in some plants. His eye was all white, so I guess they've left him there for a while. I don't like that! But I do hope they remove them dead fish when the day is over.
They usually have very healthy and beautiful fish there, and I've seen them doing water changes so... yeah.

And I still remember the beautiful, little calico Oranda that had swim bladder problems :'c He looked at me like he wanted help :'c But next time I went there to get my own two, he wasn't in the tank anymore... so I figured he must've died because of something as st*pid as constipation. Which both my orandas had too! I was feeding them lots of worms and peas for days to make them more active and healthy! And this is just st*pid since these are worth 10€ around here anyway! Isn't that enough motivation?!

I've seen multiple half eaten fish in tanks with goldfish!!! And other generally peaceful fish, so I don't think it was a case of murder or that was meant to be feed to them. At the same place, they had a show tank and there was a little black moor stuck in the plants so I told them and they just said"Yeah it's dying and the other fish are eating it" (it was in with non-goldfish). Did they not think that by removing it from the tank that they could have saved that poor little fish's life!!! That's at one of those general pet shops though who probably know nothing about fish or most animals, they probably just like puppies *sigh*

u should break into her place and steal the fish.