If anyone has experienced problems with google services or google apps after update to 5.4.2 MIUIv6-5.0 on Mi2/2S, then should try this install method which is working perfectly (tested and confirmed):
1. install 5.3.27 MIUI6-4.4 fastboot ROM with MiFlash using flash_all.bat script
2. install xiaomi.eu multilnag 5.3.27 MIUI6-4.4 ROM using MiRovery or Updater app
3. update google play services and install gmail from google play and sync it
4. install xiaomi.eu multilnag 5.4.2. MIUIv6-5.0 ROM using Updater app
5. update google play services
6. Install any google app from google play what you want
7. done
Download links:
5.3.27 MIUI6-4.4 fastboot ROM:
http://bigota.d.miui.com/5.3.27/aries_beta_images_5.3.27_4.4_cn_5ba6b88481.tgz
MiFlash tool:
http://bigota.d.miui.com/tools/MiPhone20140509.exe
5.3.27 MIUI6-4.4 xiaomi.eu multilnag ROM:
http://htcfanboys.com/download/acid/?action=list&folder=70381