Speaking of installation failures, I'd mentioned that the Tools upgrade worked in 10.11. Well, maybe not.
The El Capitan success was with beta 3. Upgrading it to beta 8 reduced the screen resolution to 1024x768 as the default and the only choice in Scaled. An attempt to reinstall Tools failed. Uninstalling and then reinstalling tools succeeded but upon reboot, the screen resolution didn't change. The solution was to reboot to the Recovery partition and, in Terminal, use csrutil to turn System Integrity Protection off (the separate panel to do that with a click has been removed). Then, after rebooting, uninstall and reinstall Tools again. Reboot back into Recovery, turn System Integrity Protection back on and reboot again. This time, the range of screen resolutions in Scaled is back, as it should be.
That experience would suggest that while the VMware Tools installation may appear to be successful, it isn't fully so unless done while System Integrity Protection is disabled.
Update: The previous observations are for a 10.11 guest running in Fusion 8. Upgrading a 10.11 guest in Fusion 7 gave the same screen resolution problem and while reinstalling Tools was declared "successful" (uninstall then reinstall wasn't necessary), the screen resolution problem remained. Again, the solution was to turn System Integrity Protection off in Recovery mode, reboot to 10.11, reinstall Tools again, turn System Integrity Protection back on in Recovery and reboot. Once done, all the resolution choices are back.
The takeaway is that the criteria for declaring a VMware Tools installation successful may need to be sharpened when the guest is El Capitan. And given the vast range of features Fusion supports in a guest, the screen resolution problem may be just the tip of the iceberg...
Update 2: Regarding Windows XP Home and XP Pro Tools upgrades, the secret to success seems to be patience. Since my Fusion 8 test is on a separate partition, I copied the two XP VM's from the primary drive which is still running Fusion 7 to the Fusion 8 partition and tried again. This time, even though the Menu offered to upgrade VMware Tools and nothing else seemed to be happening, I ignored it. Eventually, a Tools upgrade started by itself, went through the automated routine and even rebooted automatically. The XP Pro upgrade generated the Found New Hardware Wizard warnings and even an installation failure notice but I ignored that too, and apparently so did the Tools installer which just went about its business. In both cases, the Tools upgrades succeeded but only because the user left them alone.