These were the same concerns I had before buying ceramic, I really didn't want to spend the money and be disappointed. The size/shape issue was also a concern. After LOTS of research, I decided to go with the Primo Oval XL. Its shape allows for some very versatile configurations. I like that I can make 2 zones in this cooker using the firebox divider and ceramic deflector plates. I have done briskets, butts, steaks, burgers, pizza, stir fry with a wok, etc.... The shape is what sold it for me, its long oval shape accomodates long briskets/ribs, etc easier than round, in my opinion. There are some very die-hard fans of BGE, but I think I read somewhere, and tend to agree, ceramic grills are very similiar in the ceramic material used, the molded shape is the big difference. I also like that Primos are made in the U.S. Look at their website and see what you think, I just know that I have not regretted once getting the Primo.
As far as what foods are good on ceramics, besides the above mentioned, I really like to do chicken, either whole or spatchcocked, the ceramic really holds in moisture, and chicken turns out great. Steaks are good, you "bake" them first, remove, raise temp, and sear them at the end, as ceramics are eisier to get hot than to cool down. I have baked a cake in the ceramic, fun, but not too noticable than from an oven. Briskets and butts are really the best though, start them at night, go to bed, and the next day they are done, thats pretty easy cooking!! I can't really think of anything that is bad in ceramic, I will admit though, if I am doing a burger or two, I will fire up the gas, just quicker than lighting coals, but if I'm doing lots of burgers, I will use the ceramic. Hope this helps!
Primo XL Oval
BeefEater Discovery 1000e 3-burner