Secret London... Logo development

I asked a few peoples opinions on my logo design, and they all agreed that it looks best in its simplest form, without anything going on in the background.

Saying this I think that it at least needs a little more depth, especially as I'm going to be varying the colour. So I have experimented with using different shades and outlines.

I have chosen the following logo to use, as the black emphasises the lower part of the logo, which could also be seen as an 'S' and an 'L' alone. It also just works well visually, and seems the most balanced, as opposed to some of the others that look side heavy.

I have also experimented with different weights for the added text.