For me the lifesaver only reveals someone almost alongside. I have 2 problem areas with the standard mirrors.
First is filtering in London traffic where I need to spot the dispatch riders that are filtering more agressively that I am.
Second is on the A12 where although I am making good progress, some people are seriously moving and swing out to overtake at the last moment. If I use the mirror I only get the right lane. The lifesave does not help much and I would rather not accessories the back on the bike with one of the German Executive boxes
If I contort myself to get a good view it upsets my flow and I miss my opertunity.
Of course I am a little wider than some, so I diet may be the solution, but I would prefer something less drastic
Rob