Sorry, I´m pretty late here.
It took me a long time to change from windows to mac, even though so many people recommended it to me. I´m still not a fanboy. But I have changed to mac 8 years ago from a 6 month old PC that took 8mins to boot every single time I booted. In my windows history I had to newly setup the computer at least once a year to keep it running at a decent speed and without trouble. And I have tons of friends who told me the same thing.
I don´t know how much changed in the windows world since then, but my macPro that I bought back then lasted me until may this year - so 8 years without ever doing a completely new setup, or anything. All I did was give it a bigger harddrive every now and then and after approx. 4 years some more RAM. That was an absolutely new experience for me. 8 years with a computer - before that it was a maximum of 2,5 years before I bought a new one. So in the end the Mac was better and cheaper. Just lately I heard that IBM is buying macs for their employees (
here is a link). That is pretty weird even though they sold their computer part to lenovo.
Another thing I have to throw into the pro mac camp: the first time ever a backup system worked for me was when I started to use time machine. Before that not a single of 3 or 4 backup sollutions I tried managed to save all my data without errors. That sure is long ago and I hope things changed in the windows camp.
The big con against apple is that they seem to create their products only for the windows user in mind making it easy to enter the macworld. For people who used the mac for years, there were many things in recent years I had to change in my workflow just because they thought it was better the other way.
Another con is their rediculous pricing for hardware like SSDs and RAM - I buy as little RAM as possible and upgrade right after that, throwing the parts I bought out as soon as it gets delivered. Unfortunately it is not as easy with SSDs.
That said, 128GB SSD you were thinking about isn´t all that much. Install a few adobe applications, backup an iphone and ipad, and you´ll get to the limit. Sure you can always use external harddrives, but it is nice to have a little latitude in case you are on the road without additional HDDs.
In regard to external drives: I do use countless from 2-3 companies.
On my main iMac I have the interal 512GB drive for programs and OS and 4 external SSDs in a single thunderbay 4 mini OWC housing with thunderbolt connection for data, images and filmwork. Together with the internal 512GB they all are backed up to an 8GB external HDD that I exchange regularely and store the other one in my father in laws house for safety reasons.
I have a few 3TB hard drives for customer photo- and filmwork and always duplicate the drives to have two of them in case one fails. Whenever possible I too store one of them in my father in laws house.
Buying those rather expensive Backup drives is nothing I like - it´s a pain to spend so much money on something you hope you will never use. But the smaller drives are pretty well priced and I don´t really care to buy two of them if needed.
Ah yes, and we currently use 2 iMacs and a 15"macbook pro retina from end 2013 which I can even use for 4K video editing. For the latter I don´t have any backups to be honest because I usually only use it when I´m on a trip.
Now after all this "praise" let me knock on wood 100 times so that my macs won´t fail me anytime soon
Maybe that helps in case you haven´t yet decided what to do.