IBM AIX is a very powerful and extremely stable operating environment. It is well suited for applications that are business critical and cannot tolerate outages. It is best used to address large enterprise level application needs where stability and scalability are of paramount importance. IBM AIX is less useful for small enterprises.
SLES is a good fit for running supported enterprise applications like SAP, HANA, oracle,.. We use it to run all our SAP workloads, and so far everything has worked great. All libraries are right in the repository, all documentation is correct and the support answers really fast in case you have problems.
The support window for service packs after a new SP is released is too short.
Community engagement is low.
There are times when supported packages fall too far behind and create compatibility issues with applications. The Open Build Service usually provides a way around this, though.
AIX is robust, helps the systems administrator, is built to prevent easily made mistakes. If you are used to other variants of Unix (in particularly Linux) there is no steep learning curve to get started with AIX. You need to learn the intricacies of the operating system, but that is true for any new operating system. AIX has built-in tools for almost anything you want and has the AIX Toolbox (on the web) for tools that are not included with AIX by default, but can be installed. Installation of AIX is modular, you can select with components and features you want to have installed. Installation of additional components (and usually also removal of installed components) is easy and straight-forward.
For the breadth of services, features and overall performance, I believe Suse Linux is a great choice for any enterprise. It still has to grow a bit in areas like online help forums and documents, but we are pretty much satisfied with our choice.
It's great for basic support issues. But it's less suited for anything that is either obscure or uncommon, and it is very hard to escalate, unless you've built a relationship with your vendor/salesperson.
Compared to other Unix-like operating systems, IBM AIX is the one with a solid roadmap into the future and is likely to stay around for a long time (it is over 30 years old and still being updated with new features and components all the time). Compared to many Linux variants, the AIX operating system is more robust, easier to manage and well-supported by its vendor.
SUSE Linux Enterprise Server works well with the SUSE Manager, it really simplifies everything. We also do have SUSE 4 SAP, and the SUSE Manager is able to manage them all, even other (up to date) Linux distributions. Patching has never been that easy and the SALT integration is also working without any problems.
It allows a very small team to manage a large number of servers, due to its automation and manageability.
SAP supports it very well, making it straightforward to manage. There are also "recipes" for Oracle which has all of the requisites to install an Oracle DB; which helps with deployment immensely.
It lets us run large SAP instances in SLES on Power, helping us with support, manageability, and performance.
Support costs are high, but required for SLES for SAP.
