I have taken both multiple times, and in my opinion the test-center GRE is more likely to result in a satisfactory test-taker experience (and a valid score) than is the at-home version.
While the GRE at home is undeniably convenient, and a great option for those who do not live nearby a test-center, there are just too many things that can go wrong: the proctor shows up late or not at all (happened to me twice), your power and/or wifi signal drops, the technology doesn't work, crashes, and/or lags (happened once), et. cetera.
In addition, Prometric / ETS exam security may flag or even cancel your at-home GRE score for running background software (whether unintentional or not), for talking to yourself, for covering your mouth, or for going / looking off camera (yes, even briefly!)--and for a variety of other reasons, including suspiciously high score improvements, and suspected Analytical Writing plagiarism.
For these reasons, I would estimate that at-home GRE scores are 2-3 times more likely to be cancelled than are test-center scores. The at-home test is undeniably easier...but it's also a bigger risk.
Happy Holidays,
-Brian from McElroy Tutoring