I've completed an IPE MSc at the LSE and I am completing the IR/PS MPIA program.
1. If you want to work in the US, a US school is usually better.
2. The IR/PS program offers more quantitative training, and those hard skills will help you land a better job.
I enjoyed my time at the LSE more. The seminars are smaller and the workload is reasonable. IR/PS is a professional degree mill with large classes, but it gives non-quant background students quant skills and gets them out into the workforce. If I had to do it over again, I would skip LSE (unless it was for the econometrics degree).
I hope this helps.