round bales - good or bad?

All three of my horses are super easy keepers, the only time we've had a problem with anyone getting skinny was when the big guy was bullying my sisters pony away from her food. My question is...
Round bales! Are they good or are they bad? We got three today, the ones that are all wrapped in plastic, and the guy that dropped them off said that lots of people feed them to their horses, but I'm still curious. When we opened up one of them it smelled super... sweet, and even though it smelled the same last time, we had five horses eating off of them so I wasn't as worried.
What are the big risks associated with round bales? We've only ever experienced colic once (and super mild colic at that) and I'm not as educated as I'd like to be about founder and all the other 'problems' associated with feeding and I'm just worried. We have two round bales out right now (because we don't want Heidi to be bullied away from her food again) and I would just like some more... answers?
My mom is convinced it's the way to go because it's convenient, but she's not the most nutrition savvy person either.

I've never seen colic or founder problems related to feeding round v. Sqaure bales, and assuming you have a good hay source, the hay is nutritionally the same...they just bale round v. Square based on their expected demand for each. Round bales do tend to grind up the hay a bit, but that just results in a little more waste.
For easy keepers, about the biggest problem that you could have is them getting fat. If they do, just limit their access to the bale(s). Our three mares (all easy keepers) will finish a round bale in 1 to 1 1/2 weeks depending on the temperature...fast enough that we don't have any mold problems, even when it rains.

The only problems I have had with round bales are horses that get too fat off of them, lol. As long as you have at least 2 horses eating off of one, they should eat it before it gets moldy from rain. If you only have one horse or two ponies eating off of one, then you will need to put it under a cover/shelter or tarp it. It can go moldy and it will lose nutritional value if it's exposed to the sun and elements for too long.

One of my 700 lb round bales lasts two horses about 10-12 days, maybe 14 if there is anything to graze/nibble on in their pasture. We've gone to squares now because most of my horses got too fat off the rounds.

We have two out, both of them under shelter and partially wrapped to keep them from demolishing / sleeping in it (I once walked in on one of the horses taking a cat-nap and nibbling at the same time, one of those moments that you wish you had a camera on you, lol).
It's good to hear that people don't seem to be having serious problems, and considering all of the horses are fairly well worked now, here's to hoping they don't get too fat.

We only feed our horses round bales. The quality is much depending on how many layers of plastic they are wrapped in, and by that I mean how lightly it will be to find parties inside the round bale that are moldy and a danger to the horses. Also it depends on how they where harvested if there could be dirt in them, the danger of Listeria bacterias. You should check the bale every day in order to do what you can in order to find mold spots and depending on the outside temperature pay attention to the temperature on the inside of the round bale. It can develop warmth quite easily and all you can do is to remove it from the horses and destroy it if that happens. But as I said in the beginning, we feed our horses round bales all year round, except for the two summer months where they are in green meadows. It works fine for us.

Are your round bales totally wrapped in plastic (sides and around the round part) or are they just held together with plastic around the round part?

If they are sealed you are not feeding round bale hay, you are feed silage. Silage is fermented. And though people do feed it to horses I am not sure I would feel comfy with a huge round bale of it for two of them.

We feed round bales. One round bale will last the girls in the pen (Misty, Dancer and Rain) a week. We have a bale in Scooter's pen and one in the pasture for Junior that we pull hay off of for the goats. The boys will go through a bale in about two weeks. Haven't had any mold issues at all - even with the boys.

I plan on buying some round bale feeders for horses. We have some hay feeders at my inlaws I could use, but they are for cattle, and I don't want my ponies' manes rubbed off. It's a crying shame that the moment something says its for horses, the price automatically doubles!

I love round bales. Feed them during the winter, put one out and lasts 3 horses about 10 days. They usually eat practically non stop the first day, then eat at intervals during the day between napping and playing in the snow. Our bales that we get are wrapped in twine which I go check daily to pull out the broken strings.

We pull the strings when we set out the bales. A habit we got into when we fed cattle. Piece of advise for anyone pulling the strings, whether you pull them when you set them out, or over time. We cut the string and pull it off of the bale. DO NOT PULL THE CUT STRING WITH AN OPEN KNIFE IN YOUR HAND!!!!

Note to self - listen to the above advice and you won't slice your thumb open!

I have two of the 32" round feeders from AGI. They have really held up well and are MUCH more affordable than the big metal feeders. They are a PITA to put together (LOTS of bolts...), but very easy to move around and maintain.
HAY RINGS