The London, Tilbury & Southend comparison is by and large invalid, talking about similarities or differences.
c2c: Only operate Class 357 Electrostar units, with very similar (or identical) acceleration and braking. Train Calling patterns are by and large similar, although a few peak services are non-stop to Laindon IIRC, There is a small amount of freight to Tilbury, but that's it. It's a 2-track railway from London Fenchurch Street.
Greater Anglia: Operate Class 315, 317, 321, 360 & LHCS services, with contrasting acceleration and braking. Train Calling patterns differ massively: on GEML there are non-stop services to Colchester and Ipswich running alongside services which call at Stratford, Shenfield and all stations to Witham. There is a substantial amount of freight on the route to/from Felixtowe, as well as the North Walsham to Harwich tankers and Ipswich Griffon Wharf to Rugby DBS Intermodal trains. A 4-track railway from London to Shenfield, 2-track thereafter.