There is a known issue with XD 7.1 / 7.5 when opening Excel files. It takes longer than usual (in my case 12sec) when opening an Excel file. Opening just Excel works as expected. That’s a known issue, a private hotfix is available. Reach out to the Citrix Support in order to get the hotfix.
Update, 03.06.14: There will be a public hotfix very soon: XD710ICATSWX64004
By default, Adaptive Display Generation 2 is enabled when you install XD 7.1 or 7.5. If you don’t change it to legacy graphics mode, you will have the issue. You’re not affected if you enable the legacy graphics mode (Adaptive display gen 1). So this is indeed an issue of the new adaptive display gen 2 version. We experience other performance issues us well with adaptive display gen2, but I haven’t found a solution yet. For instance, performance on FAT clients is fine, but not on Wyse Thin Client C10le. Legacy graphics mode works fine. Troubleshooting is going on….