We found the check-in very smooth, and the system that was used (keyless & you use your mobile phone) to begin with, was great - would love to know how it works. Antonio's communicated and speed of response was excellent. It's a well located flat, not busy, nice atmosphere & vibrant with a mix of students and seniors. The flat was a good size for the three of us, and had all we needed. It's good value, accurately described. There're a few cafes nearby, and it was great to see people chatting, and there's a great gelato store just across the street - try the lemon and basil :) You get a feel of Rome life without all the tourists. Also handy is the direct train to the airport (from Tiburtina, which is a few minutes walk away).
If you do stay, there's a restaurant nearby - Taverna del fuorisede, which is worth a visit. There's a really nice atmosphere, frequented by locals (students & families).