At present, during school holidays and at the time of the centenary of the beginning of the war, you are likely to have to queue or face timed entry to get into the galleries, but when you do there is certainly enough information to go around. In fact, the approach of the new galleries seems to be to engage everyone individually all the time, rather than making it a collective experience, which is rather welcome. The galleries, designed by Foster & Partners, inevitably examine life on the various fronts, via photography, video, first hand accounts, interactive push-button distractions and original artefacts. It's well worth a visit if you can find a quiet time to do so.
For more, see http://www.iwm.org.uk/exhibitions/iwm-london/first-world-war-galleries