I recently got the owner of a Samsung Galaxy Ace Plus. My conclusion about the phone is positive.
Although it has not such a nice display as my Galaxy SII, but considered for the display looks nice and combines all the functions which must have a modern smartphone.
The workmanship is good and looks solid, the camera takes good pictures and the Ace is compared with the SII almost as quickly and with the usual applications (Tagesschau, Spiegel Online) is noticing no difference in performance.
Only the display is of course a bit smaller, so that can not be accommodated as much as shortcuts for larger displays. But this is not tragic, since you simply can rüberschieben screens.
For WhatsApp problem, I have an Android Forum following tip found, the worked great for me.
Invites you to WhatsApp (as Android version) on your PC and then can ye this email (to an address on the access it with your phone can) or USB cable to your phone and then install the app from there.
After that, everything is like all other smartphones. And works flawlessly. Although is more cumbersome than a direct download but it works.
CONCLUSION: For the price a great smartphone, its inner values are top. Who is already undergo slight smears and no headphones need the get good value for money at the display. Because up at the screen I see no difference from the Galaxy SII. The battery lasts even longer, since the display also do not need much electricity.