Started using HANA 5 years ago with v1 SPS5 back when it was just released for SAP BW. Back then it was "only" an in-memory DB. With each new SPS release, HANA became better with more DB features integrated. Fast forward to today, it is a full-fledged database platform with enterprise features that rival (and in some cases) even bests Oracle, MSSQL, DB2, et al. For customers who intend to use SAP for the foreseeable future, you would no doubt have HANA already as part of your existing if not future SAP roadmap, given that support for the traditional DBs is until 2025.
SAP HANA, which is re-written from the ground up to fully take advantage of today's modern hardware, supports multi-threaded CPU architecture, use of terabytes of memory to run its in-memory database capabilities, columnar & row based database with full-fledged compression, full support of PL-SQL and many other application components.
From a hardware perspective it is a 2-horse race with the commodity Intel x86 platforms becoming more powerful with each CPU iteration and better CPU core-to-memory ratio support, and IBM with their Power-based CPU architecture. As hardware prices continue to fall and become more powerful, it is only a matter of time before HANA hardware becomes truly commoditised.
Today SAP HANA is not only a competent database platform, but also is a very robust applications platform. As HANA continues to grow its feature set naturally there are more bugs as a result of a multitude of features. Development of SAP HANA is also diversified across multiple locations around the globe (Walldorf, India, etc.). SAP must do a better job in responding quicker to customers with issues.