This only discusses my thoughts on Aldora dive shop.

Made a quick trip to Cozumel just over a week ago.  Dove with Aldora
(www.aldora.com) for the first time in about two years.  There have
been changes and overall there were good points and less than good
points.

Changes:   None of the DMs were recognizable.  Everyone was new to me.
Although Memo Mendoza is back (great guy), he runs the place.  They
are converting over to tanks (valves) that allow either DIN or yoke
regulators to be used (removable insert) so if you do not want your
regulator converted to DIN, you should not have to.  The conversion is
not 100% but I used my yoke setup the entire trip whereas before I
used DIN.

They are stopping at Nachi Cocom for the surface interval instead of
Playa Sol.  This is great.  Playa Sol was too loud and catered to
cruise ship folks. So it was not ideal.  Nachi Cocom is mucho better
and more picturesque IMO.

Good Points:  

1)  Dive Duration - Up to 120 cu ft steel tanks mean longer dives for
most people.  Most first dives were 60 minutes whereas a person
reported first dives with Sand Dollar I believe were typically 35
minutes.  Of course a few people can make two hour dives to 200 feet
max depth using twin Spare Airs, but most people will not make 60
minute dives on AL80 tanks. (If someone can show me that the typical
first dive to 100 feet on an AL80 lasts an hour, I will correct my
assumption - This means the representative person from a typical dive
shop).

2)  Surface Interval - Approximately 1.5 hours on a beach, with
restaurant, restroom, pool, lounge chairs under palapas.  Compare that
to sitting on a boat travelling to the next dive site then sitting on
a rocking boat.  Personally, I prefer to run my feet through the sand
while watching a sailboat go by, listening to the waves gently lapping
on the shore (see picture at link below).

http://www.pcisys.net/~ronlee/Scuba/Cozumel/July2002/SurfaceInterval.jpg

3)  Boats - Six passenger and fast.  There are others as fast but if
Aldora's were slow, the other good points would be adversely affected
by taking all day to get to the dive sites and back.

4)  Dive Site Selection - Typical...group consensus.  Southern dive
sites normal for the first dive and no extra charge.

Negative Points:  These are negative things from my point of view and
very likely will not be a factor for many divers.

1)  Dive Duration - They seem to only want to go one hour.  On three
dives I came up with 1200, 1300 and 1400 psi of air and I am not the
best on air consumption. (I did not note the ending air on three other
dives).  One dive, Palancar XXXX then Palancar Gardens was also only
60-65 minutes even though I could have gone 90 minutes.  Perhaps I got
on boats with people with worse air consumption than me, but when I do
things to equalize air consumption such as drifting higher than the
group, why cant those people do the same?  Since I could not assess
the air status for other divers, maybe things just worked against me
this trip...or maybe Aldora only seeks one hour...then everyone up.
If the later, then they are regressing towards mediocrity.

2)  Mother Hen Syndrome - I don't appreciate the briefing were the DM
says "Don't go below me, don't get ahead of me."   This may have the
veil of "safety" behind it but my response to that is poppycock.  I
don't need a DM to make me safe.  I have made dives in places far more
challenging than Cozumel without a DM and done it safely.  30 or 50'
lower for a short duration is not a safety issue.  Getting ahead is
not a safety issue.  I can get track of the group and should I have to
surface separately, I can do it safely.

The reader can make their own opinion about my negative points.  Other
than those, Aldora does offer a dive experience that I believe
surpasses that from a dive shop that uses AL80 tanks (and does their
SI on a rocking boat).