The latest is that Caldera Vista has replaced Naxos Jet, which previously replaced Andros Jet. Sea Jets seems to have an endless supply of old clapped out highspeeds.

I am happy to report that my experience with both Seajets (bigger) high speed Andros (I think it was Naxos on August 4) and Blue Star's Delos was great. Seajets left Rafina at 3:15 (scheduled 3pm) and arrived on Paros about 30 mins later than scheduled. Blue Star left Paros 5-10 mins late but was delayed en route (traffic in Naxos port) and arrived about an hour late to Santorini. While Seajet high speed was smaller in size, the on board experience was not dramatically different (yes, Seajet was rougher at times); The Blue Star was very crowded this time of year (August) so I do recommend getting an assigned seat for a couple of extra euros. Thanks all for help planning!

Only time I would disagree with Heimdall on Blue Star business seats vs. "aircraft-style" Reserved-Economy seats is if you have a long 5 hr trip in the evening, and hope to doze a bit. The "air seats" are really MUCH better than current airplane seats -- lots of leg-room, footrests, lean-back etc, AND have a head-rest too. The business-seats are leather "club chairs", comfy seating, but arms & back are all one piece/one level, can't lean back enough to nap much. There also are curved couches and on less-crowded longer trips, some passengers will hog a whole couch section to lie down on, but, not my thing.

Yes I have taken business class twice, and just was reporting my experience -- it was affected by my need for rest, on sailings that were just busy enough that sofa-hogs left me with only an upright club chair. For others, the view and the waiters may be the deciding factor.

Fair enough, TJ. Some of our fellow travellers aren’t very considerate. It’s enough to make me prefer flying to the island and back. Get there in 40 minutes and take your nap in the hotel room.

I'm with you there, pal. Time is precious.

Thank you for the Blue Ferry details @travelerjan and @heimdall! I was running around trying to film the experience for my youtube channel)) but it was so crowded in the open seating areas (including business) that I did not notice the chair difference between business and air seats (or maybe i was too new/shy to filming). I did manage to take a peak at the cabin as the attendant was changing the sheets. It seemed that all seats were taken in the open areas though between Paros and Naxos (a lot of people got off at Naxos)- I was able to doze off at my comfy window air seat and went outside couple of times for some fresh air and scenary filming. I am already thinking next trip. I love naturally gorgeous beaches with blue water swimming (for hours, so preferable shallow so i dont worry about my kid), picturesque old towns (ideally not as crowded as Naoussa was this August))), and historic sites would be a plus but not a requirement. Milos? I know i need new threat for that, but just thought i 'd throw it in here since i am still in the Greek mood. Thanks for all the advice!

Weekend celebrations --- I think you'd do best by starting a new thread, because some knowledgeable people may not open a long thread just titled Greek Ferries. Here;s some info to share, to get the best advice and avoid advisors having to guess:
• TIMING - When? If August, to avoid crowds may require distant islands, maybe without airports, perhaps beyond Cyclades.
• HOW LONG - a week? 2 weeks? if latter, a larger island, or consider 2 islands
• CAR? - if u want to do without a car, isle needs to be v small & walkable, or have good bus network, like Naxos/Paros. Milos bus network very lame in May-June and I hear not much better even in High season

Anti-crowd strategy includes knowing what isles have airports that accommodate jumbo jets and direct flights from Europe, are stops for mega-cruise ships, and/or promote package-holidays with purpose-built "resort" areas. Islands like Sifnos, Milos, Serifos, Kithnos are somewhat self-limiting because they have a finite number of accommodations -- so beaches can't get as jammed. The downside is that these islands "fill up" farther in advance for High Season.

I made 9 ferry rides between July 4th and July 21st of this year. Non of the following ferries was crowded (some of them looked half empty):
FB Knossos Palace
FB Nissos Samos
FB Pegasus Express (2x)
FB Marmaris Express
FB Artemis (2x)
BB Bluestar 1
FB Bluestar 2

@neckervd would you mind sharing the directions? I think it's important too. Paros-Santorini might have been as busy as it gets but it was very very crowded
@heimdall i am glad you did not mention the ferry tragedy Before my trip. I am an anxious traveller, would have been very worried...
@travelerjan thank you for your island choosing thoughts...i will post a new thread when i get closer...definitely Car but read some dirt road (4-wheeler) concerns to reach Milos beaches, so something to consider

" @neckervd would you mind sharing the directions?"

The names of the boats are self explaining.
But if you want to know all the different legs, here they are:
Iraklio - Milos - Piraeus
Piraeus - Chios
Mesta - Aghios Efstrathios
Ayos Efstrathios - Lavrio
Lavrio - Kea
Kea - Syros - Paros - Naxos - Ios - Sikinos - Folegandros - Kimolos
Kimolos - Sifnos - Serifos - Paros
Paros - Patmos
Patmos - Leros - Kos - Rhodos

BTW: Express Samaina was just one link in a chain which began with SS Heraklion (Typaldos Lines) and went on with MS Heleanna (Efthymiadis Lines), Panagia Tinou (Ventouris Ferries), MS Sea Diamond (Louis Cruises, today Celestial Cruises)........

@neckervd, thank you! what an impressive summer itinerary! (and food for my thoughts!)