My thoughts about using free services is that it depends what you're using the site for. If you are promoting your web design business, lol of course you don't to use a free site builder to show that, right?
If you are promoting a business of any sort it is better not to use free sites unless you can disable the signs that it is free such as advertisements or links to the site builder.
You can get hosting for less than 5 dollars a month, so if you have a business site, five dollars a month is nothing if you want to make sure to put your best foot forward.
If you have just a personal site, then I'd say it's fine to use the free version, but then I wonder if you can do it for less than five a month why let someone else make ad money off your words?
I'll write an article next week about this, look for it on Thursday.
Stephanie
My Blog: 
. But, I bet if you looked up what you want to learn on YouTube you'd find it. I find everything there. I even found out how to put rubber bands on my daughter's braces there. 