Getting the right echo timings and amplitudes is just the tip the iceberg in replicating the sound of the Meazzi's, as noted by Dave and others.
Most of their characteristic sound comes from the way both the dry and echo signals are distorted and compressed. For example, if you play the top 3 strings of an "open" D or E chord at the 12th position with a properly set up Meazzi, Long Tom or TVS3, you will be able to hear a whole raft of additional tones resulting from intermodulation distortion, some harmonically related and some not. In particular, there will be many tones at fairly low frequencies and these are responsible for thickening up the sound and giving it a bit of "growl". The amount of these tones depends upon the drive level, and that is just the dry signal. Add to that the additional artefacts introduced by the compression and distortion of the echo signal and their interaction with the dry signal, then add a bit of wow and flutter, and you start to get an idea of the complexity involved. While I haven't tried the Strymon, I have yet to hear any digital device that comes close to replicating these effects in any accurate way, including those with analog devices like FET's in the signal path. Of course, for many players these subtleties are not regarded as important and so any echo unit that generates roughly the right echo timings is fine (and probably a lot less expensive). Also, many may have no interest whatsoever in replicating a Meazzi sound and will want to explore a whole range of other sounds and for these the digital platforms provide a lot of flexibility.
Paul.