I run my box wired, but I have also tried it wireless and I notice no difference. I then have a Smart TV which is wireless and this is fine and finally 2 x Firesticks upstairs, again both wireless. The Wi-Fi signal in 1 of the rooms upstairs is excellent, the 2nd room is not very good, both still run fine with IPTV, streaming etc. Finally I have an Xbox and a PS4, both run wireless, the connection doesn't drop out, but it's nowhere near as fast as wired for downloading.
Wi-Fi all depends on internal factors, the thickness of your walls, materials used for construction, distance from router. Wired is always recommended as the best option, but only you can tell whether your Wi-Fi is up to speed, everyone is different. Even next door making a baked potato in a microwave can potentially affect your Wi-Fi.
Plus, you know your I55 box inside out now, so why would you consider buying a different box, why not just buy another of the same box, at least you know how it works and saves you having to learn a whole new box all over again.