Often the faster an algorithm can be put into the market, the more advantage it has. Many algorithms have a shelf life and quicker time to market is key in taking advantage of that. With the community around Java and the options available, it can definitely be a competitive advantage, as opposed to C or C++ where the options may not be as broad for the use case. Sometimes, though, pure low latency can rule out other concerns. I think currently, the difference in performance between Java and C++ is so close that it's not a black and white decision based solely on speed. Improvements in GC techniques, JIT optimizations, and managed runtimes have made traditional Java weaknesses with respect to performance into some very compelling strengths that are not easy to ignore.
G1 GC is an incremental parallel compacting GC that provides more predictable pause times compared to CMS GC and Parallel Old GC. By introducing a parallel, concurrent and multi-phased marking cycle, G1 GC can work with much larger heaps while providing reasonable worst-case pause times. The basic idea with G1 GC is to set your heap ranges (using -Xms for min heap size and -Xmx for the max size) and a realistic (soft real time) pause time goal (using -XX:MaxGCPauseMillis) and then let the GC do its job. With the introduction of G1 GC, HotSpot moves away from its conventional GC layout where a contiguous Java heap splits into (contiguous) young and old generations. In G1 GC, HotSpot introduces the concept of “regions”. A single large contiguous Java heap space divides into multiple fixed-sized heap regions. A list of “free” regions maintains these regions. As the need arises, the free regions are assigned to either the young or the old generation. These regions can span from 1MB to 32MB in size depending on your total Java heap size. The goal is to have around 2048 regions for the total heap. Once a region frees up, it goes back to the "free" regions list. The principle of G1 GC is to reclaim the Java heap as much as possible (while trying its best to meet the pause time goal) by collecting the regions with the least amount of live data i.e. the ones with most garbage, first; hence the name Garbage First.
We never intended for a support contract to be required to keep JDK 7 up to date. TZUpdater was made unavailable on March 8 as part of the End of Public Updates for JDK 6, and as soon as we learned that this affected JDK 7 users we initiated the process of making it available for JDK 7 again.