These are the possible caveats with FOSS and commercial software:
1. Free software and price – advantage: free as in free beer and freedom
2. Free software and technical support
- RTFM, GIYF
- ask the community
3. Commercial software
- Closed source
4. Commercial software and technical support
- Paid tech support
5. Free/open source software, commercial tech support
- I can’t think of a caveat here except perhaps your budget (best of both worlds)
Note that there’s no such thing as commercial software with free vendor technical support (tech support is different from documentation). Also, this does not imply that you don’t RTFM with commercial software.
The essence of free/open source software is that, you have the flexibility to
- mix and match packages from FOSS that suits you (remix)
Also, note that this post does not imply you use either FOSS or commercial software.
It implies that the best software is entirely subjective. The best software is the one you know how to use.