Any settings lower than 1500 increase the amount of packets your ps4 is sending into the PSN servers. Not only will this setting not affect your chances of getting online. But continue to flood the already bogged down PSN servers! Here for those of you who just ALT F4 and jump up in the air when told to do so... "A maximum transmission unit (MTU) is the largest size packet or frame, specified in octets (eight-bit bytes), that can be sent in a packet- or frame-based network such as the Internet. The Internet's Transmission Control Protocol (TCP) uses the MTU to determine the maximum size of each packet in any transmission."