It would really depend on a few factors. First and most important are the type of frequencies used with U-Verse. Our HS-8 splitter can handle up to 1000 MHz or 1 GHz. Our CVT-2/8WB can handle up to 1.5GHz however is not compatible with the most current versions of MOCA (multimedia over coax). So finding out the frequency requirements is important. The amount of insertion loss between using a 4 way and a 3 way is negligible compared to the 8 way, there is an extra 1.5dB loss using the 2 splitters instead of the single but this should not greatly affect your signal in any way. It is also important to confirm whether the existing splitters are passive or powered, if you remove the two powered splitters and replace with a passive splitter it may affect your signal strength quite a bit. Contact Channel Vision directly if you have any further questions.