Hey man,
Congrats on getting into LBS. I just got in as well and am Asian American with experience in Asia so I can speak a little about this.
In terms of network, when I went to the Kellogg admission event in Shanghai this past summer, one of the alums told me there are over 300 active alums in the Shanghai Wechat group. The network definitely seemed pretty strong. Unfortunately, I didn't attend an admission event for LBS in Shanghai. If I had to guess, I would say Kellogg's network in Shanghai/Asia in general is probably stronger, and I do feel this is probably true for most American schools.
According to Linkedin, there are 500+ alums in China for both schools
https://www.linkedin.com/edu/alumni?com ... m-CN-titlehttps://www.linkedin.com/edu/alumni?id= ... chg-schoolDespite the numbers, I would probably still give Kellogg a slight advantage in terms of long term network in Asia.
In terms of experience, I definitely think going to LBS will give you a more global education (class demographics, language requirement, London location). This is probably very clear to you, so I won't go much into it.
In terms of MBB placement, LBS stacks up equally with Kellogg despite the finance reputation. For Kellogg, class of 2015 has 34, 26, 28 (88) going to Mckinsey, BCG, and Bain respective in a class of 635. This does include one year MBA's and I've heard a lot of these are sponsored? Not too sure. LBS has 31,21, 12 (64) for a class of 394 in 2014. The story here is clear - both schools are top tier for aspiring MBB consultants.
I'll also add that I found LBS's culture to be really close knit as well. I visited Insead and LBS back to back and found LBS's culture to be on par with Insead despite the commuter school/finance reputation. Not sure how it compares with Kellogg though.
Best of luck making your decision and maybe see you at LBS next year. Feel free to PM me if you're interested in talking more about Asia/China!