what's the difference and which do you prefer? is one easier to work with and smooth onto a cake?

They both can be a bit of a pain to make...
well, not so much a pain, but they are a bit of a process and take some time. You have to be careful that your sugar syrup is heated to the correct temp to kill any bacteria, etc in the egg whites.
I usually make IMB, but I think the diff is that swiss meringue bc uses egg yolks? Can't be too sure.
One HUGE difference is that IMBC is very stable and holds in high heat whereas the Swiss doesn't.
Try both and see which one you like. They are both nice and smoot...I find IMBC more buttery.

Good luck!

thank you! i've tried IMBC but will have to try SMBC to see the difference...was just curious to see what all the experts out here use and prefer

Both IMBC and SMBC are egg white-based icings. They both contain the exact same ingredients but the process in putting them together is different. For IMBC, the sugar is in the form of hot simple syrup. The syrup is beaten into uncooked egg whites to make the meringue. For SMBC, the egg whites and the sugar are heated together to about 140-160F, then the warm egg white/sugar mixture is beaten into meringue. The butter and flavorings are added the same way for both recipes. I make both versions all the time, and I find that they both taste about the same and handle the same, also. I prefer the SMBC because I think it's easier to make - you don't have to worry about the simple syrup hardening into little balls as it hits the raw egg whites like you do with the IMBC. French Buttercream contains either whole eggs or egg yolks. I don't care for it too much! To me, it tastes like buttery scrambled eggs. Alton Brown made that on his "The Icing Man Cometh" episode, so I thought I would give it a try. Bleck! I love Alton, but that recipe did nothing for me. Good luck!

thank you!!

Just like you I did some research & I made both BC unitl I got used to them. I found that I preferred the IMBC. It's stronger b/c of the simple sugar. Either one is GREAT to work with...

Have fun:-0)

Forgot to say that they freeze very well.
Last week I was putching around & decided to mix some IMBC with with the regular (I hate all that shortening) stuff they worked pretty well!

I use the Swiss....and think it is absolutely drool inspiring! That is my BC of choice. I made the IMBC years ago (the recipe I made was so huge though, this was in my inexperienced BC days....and the meringue almost spilled out of the mixer...13 egg whites!) and had no idea how to "bring it back" from refrigeration...so I threw it away! (ACK!) As far as the cooking of the whites is concerned, I use pasturized dried egg whites that I reconstitute. The only problem I've had with that is that they often get clumpy. If I'd only go buy myself some more cheesecloth......

Oh and I've flavored the Swiss in raspberry, chocolate and a hazelnut mocha (LOVE that one....and it's in my fridge....no...must resist temptation!)....

I'm off to do some yoga, to distract myself from the BC in the fridge!