IMO the high & consistent quality of shots pulled with minimal experience with this type of machine (E61/HX) and the ability to pull shots as fast as I can are the strongest points about the ISOMAC Tea.  If heavy duty construction is a reflection of durability then with proper maintenanace this machines is going to be around for a significant period of time.

1.  Inconvienient access to the pressurestat.
   
2.  Relatively small water reservoir with no visible water level indicator. Specs say 3L, the auto shut-off cuts in with ~500 ml remaining in the reservoir.
   
3.  Cost, the relative gains per dollar vs. a SolisSL70,Silvia etc.
   
4.  The "manual use and maintenance"

VERY 1ST IMPRESSIONS:
Unpacking this unit you will realize how heavy (21kg) it is for the relatively small footprint.  The 2mm thick mirror finished stainless steel casing that forms the back and sides weighs in ~4kg.  Likewise the "commercial" grade portafilters are nice and massive (624g with double filter basket).  The "manual use and maintenance" is in need of improvement in two major areas.  It's a little vague (ex: "push up the coffee lever and wait until water runs out from lower part of the erogation group" = push coffee lever all the way up, not just to the pre-infusion point) and the translation is a little off (ex:"plug off the cave" = unplug the unit).  The factory pressurestat was set so the coffee manometer read max of 1.4bar.  From various forums people have suggested resetting the machine to read no more than 1.2bar.  The reason why? Supposedly long idle times (>15min) results in water temps in the HX getting too hot.  From my limited experience with the TEA, this requires a significant amount of water (~300ml)to be flushed.  Access to the pressurestat requires a bit of effort.  It is visible through the ventilation slots located under the top/cup warming tray.  Trouble is the slots are too narrow & not really aligned properly to stick a flat head screwdrive through.  You must remove the H2O tank, unscrew two phillips head screws that hold the ventlating/inner top-back, then LIGHTLY flex back this chunk of sheet metal.  An alternative is to remove the six screws holding the back/side outer casing then remove the inner top/back.  The pressurestat is brass, the screw seems to be a soft metal, the directions to rotate for +/- pressure are clearly imprinted on the pressurestat.  A 5 minute counter-clockwise rotation resulted in decreasing the manometer reading by~0.5bar.  Thanks to Chris @ chriscoffee.com for his warnings, advice & assistance.  I've reset my machine so the coffee manometer reads 1.2bar at max.  It has reduced the flushing of water down to ~150 ml.(probably the volume of the HX). At that point the spluttering/steaming water has become a nice smooth flow.  If you pull shots one right after another there doesn't seem to be a need for any more flushing. IMO the right out of the box consistent good quality of shots makes this machine a "good value". The heating elements capacity, boiler design, E61 group, pre-infusion & smooth pressure build up during the extraction process all must contribute to the quality of the shot. The frequency of "god shots" will improve with roasting/blending/grinding tweaking and more experience with this machine.

Purchased the machine from chriscoffee.com.  The package of the TEA & MazzerMini was a fair price. It arrived the same week I placed the order. Pre and post purchase customer service has been EXCELLENT.