I'm not "taking the plunge" yet but I'm doing a "risk assessment" involving this machine. Microsoft tells me I'm eligible for the upgrade. I've been subscribing to "Driver Manager" for my entire fleet of Acer computer (I have 4) several of which are now truly ancient/obsolete, but still function under Win XP, Win Vista, and Win 7 (x64). Obviously, I will do a complete system backup to my NAS before atttempting the upgrade, and can therefore "revert" using the CD and backup/restore software I also liscence. This particular machine seems to be somewhat of an "early orphan" in the migration from Windows 7 with 32bit code to Windows 7 with 64 bit code, but it has remained in service and run well since 2010.
What should I "look out for?" Obviously, Win 10 is likely to be a RAM hog, and I will not consider trying it unless I can first successfully upgrade to the full 8gb address space the motherboard is supposed to support. Right now I'm having compatabiliy "issues" with 2gb DIMM modules ordered specfically for this machine which prevent me from successfully making that upgrade.