Southend is clearly not a replacement for LGW; no interlining possible. It COULD though serve as a London destination for the Cornish businessperson who needs to visit the capital; EZY's A319 service to SEN takes only a few minutes longer than FlyBE's Dash 8 to LGW. The direct rail line from SEN gets you into Liverpool St in 53 minutes. Transit times through the efficient new terminal at SEN are minimal, so that saves a few minutes. It's certainly not LGW, or LHR, or LTN, but it is about all NQY is likely to get in the London area and it can compete with the often unsatisfactory and expensive train service. At least you get a seat on an A319, you don't always on an HST....