• quality construction (stainless steel frame and  polished stainless steel on outside) (not stainless steel shell like single boiler  Breville)---> "built like a tank" description definitely applies here
  
• E61 group with preinfusion---> google benefits of E61 group  and preinfusion
  
• 0.75 litre boiler (appears to be copper) ( and insulated as purchased from Chris Coffee) and 3 litre water reservoir (one tip I recommend is use funnel with tubing so that  can refill reservoir  using water pitcher to minimize moving the machine)
  
• makes excellent microfoam milk that I can pour latte art (apple, heart, rosetta are limit of my skill)
  
• dual PID (extra cost) controls brew and steam temperature gives idiot proof temperature control w/o temp surfing ) --> important as machine not plumbed
  
• small footprint with respect to width  (because it is single boiler dual use machine)
  
• large drip tray (46 ounces)
  
• pair this Alexia with PID with a quality grinder (e.g. Mazzer Super Jolly grinder,  Baratza Vario or better grinder) and you will be a very satisfied  espresso drinker

• cost--> Alexia with dual PID costs as much as heat exchanger machine;  since W.A.F. was paramount for me I needed small footprint machine and well constructed machine.  The remaining allloted  space I use for the grinder (more important than machine anyway).  
  
• it's single boiler dual use machine--> so multiple milk drinks will be chore (see comments in detailed commentary below)
  
• to access OPV valve one must take off the shell ---> this is resolved on current version Alexia that Chris Coffee sells

See above positive and negative points.

I have added no burn steam arm with four hole steam tip to the Alexia with PID as it looks better than original steam arm.  I am still able to obtain microfoam that is latte art worthy.  Chris Coffee sells both.

I only make 2 milk drink (cappucinos and lattes) per day for the Boss.  I find the time from brew temp to steam temp about two minutes.  Certainly if you have no desire to wait or if you make multiple milk drinks per day then seek out heat exchanger or dual boiler machine.   F.W.I.W. once a year I have in-laws over and make 12  cappucinos or lattes in a row.  It takes me about 45-60 min to make these 12 drinks in a row. [ I brew three espresso, get machine to steam temp, foam enough milk for three cappucinos, force water from reservoir into boiler to cool boiler to brew temp (while pouring the milk for latte art) then extract next three espressos.  And then get machine back to steam temperature .....]   I certainly do not recommend Alexia for parties where everyone wants cappucinos and lattes!

I have had this machine for two years.  My next machine upgrade will be to LaMarzocco GS3 or Kees Speedster.  And that will occur only if I  get infusion of cash from the Bill and Melinda Gates foundation and if Boss gives me more kitchen space.  Since both of these will most likely not happen, I plan on just upgrading the espresso grinder (e.g. Compak K10).  I have asked and been told for straight espresso that Alexia with PID is that good for espresso only.  Again contribution to quality of espresso is grinder >> machine.  Alexia has survived two years w/o upgraditis save the no burn steam arm.

But perspective customers need to realize that for about $400 more then you can step up to premium heat exchanger such as Andreja Premium or Rocket Giotto  (but no PID) and for about  $1000 more get PID dual boiler like Alex Duetto.   If you are considering the Alexia, then make sure you fit its intended niche.  I realize this is small subset of home espresso espresso  users which I apparently fall into.

Chris Coffee.  I purchased this and nearly all of my espresso equipment from his store. He and Mary (customer service department )take the time needed with me, are extremely knowledgeable, and are never pushy.  His customer service is the BEST I have experienced for any purchased consumer product (e.g. luxury watches, clothing, luxury automobiles).