Question about a speakers sensitivity on its sound

I read that higher efficiency speakers eg. 93db tend to sound much quicker and more dynamic than low efficiency speakers is it true?
also read that lower efficiency speakers tend to sound slow but have more 'weight' and fullness to the sound....

Is this true I thought the only difference was output efficiency ... the reason I ask is I was thinking of upgrading my speakers (87 db) to something more efficient..
Eantala, Getting the first few watts of output power is crucial.For every 3db gain in efficiency, you are able to cut your amplification in half.10db, one tenth.The important thing to look at is that the higher the efficiency,the less power you will need to attain a similar SPL level.Most of the best audio gear is around 100w/ch or lower.If you need high quality and high power ,you will pay!
In your situation, even 90-93db efficiency would give your power amp 3-6db more headroom and would probably sound better in a direct comparison.Hope this helps-Tom
You mention speed: speakers' efficiency does not necessarily mean speed.
As to db, +6db in sound level is perceived twice as intense (all other things being equal)... 1db being the level of perception (or perceptible change in intensity) of a "normal" ear.

I suggest you favour speakers whose sound you like -- true, the more efficient they are, the less horse-power you'll need to drive them (which doesn't, unfortunately, make quality amps very much cheaper).

Sound should be your first choice.Though high efficiency gives you more amps to chose from.
You might also want to refer to Sean's post on 3/18/01 titled Speakers/SPL's/RMS Power. (No, I don't have a photograhpic memory -- I didn't really remember this so much as stumble across it when I was doing some research after reading your post). Cheers.