Has anyone used Stratix-V GT 28G SerDes?

We are preparing a design which will use 4 lanes 25G transceivers, and now only Stratix-V GT can support this speed. Has anyone used Stratix-V GT in your project? It seems there is little info about 28G SerDes, and I don't know how it performs (PCS support? BERT?), especially compared to Xilinx Virtex-7 GTZ solution. Thanks very much!