I don't see any problem with their recommendations. Their bikes are essentially refined versions of older regular road bikes from the 1960s & 1970s. Their fit is essentially the "big = comfortable" high bar touring approach from the same time period. The puffing is really great, though!
But it's different from a racing fit, and folks seem to have forgotten how things used to be. Racers with smaller tight frames and regular folks with bigger comfortable bikes. Roads were generally pretty bad compared to today, too. So we always had a 73 parallel light fun bike with Campy NR and tubulars, fit pretty small (55 for me) and a utility touring bike fit bigger (57 perhaps). Now the utility road bikes have generally gone away at the high end, although they're around in the less expensive models. Have to look, many low end models are imitation performance bikes.
From Dave Moulton, I'd run a 55 x 55.25 w/ about a 118 mm stem ideally. TT + stem of about 67 cm. Can think of that as 55 square because todays seat tubes are a little steeper. Another chart of his, 55 has a reach of 67.5 and drop of 8.7. I actually run 54.5 + 12.5 = 67 cm, and 8 cm drop. Which is OK, because my head tube angle is a little shallow, so longer stem shorter TT is the way to go.
My fit by a real master in 1974 gave me 21.5" TT = 54.6 cm and I ran a 100 mm stem. 64.6 cm. Was always a little cramped on that one.
My touring bikes at the time were generally 23" frames, so that would be about 22.5 or a bit less ctc, 57 cm ctc say. TT were probably 57 cm and I'd run a 90 mm stem jacked up level with the saddle, reach of 57+9 = 66. I'd run the saddle back and these were probably 72 parallel frames. I'd set one up and sell it to the first guy who liked it, but they were all about the same. Nice British touring rigs. Bikecenntennial got folks interested in touring and I could do a bike up well, so the market was there. They all rode about the same, too. I'd forget what I was on!
"Rivendell" would put me on (low end of their scale) a 59. I'll look at a Bleriot. 72 x 71 w/ 5 cm rake and WAIT - this is for 650 tires!! Will never do. Let's find a 700C. OK. Homer Hilson, 72 x 72, 59 x 58 with an 85 cm standover. That's WAY up in the air for me! And very far out. Put a 90 mm stem on it and I've got a reach of 67. Hold on, that's just right. I could actually ride that setup! With the bars up high, I'd be tempted to put a 100 or even 110 stem on it.
But would I like a Hilson? It's just a little bitty bit bigger than I used to tour on. The geometry is nice. I bet I'd like it. I think a 58 or larger would just be a bit huge.
But wait, that's about the same geometry I used to tour on, but a little undersquare to get the bars up. And many people used to ride big frames back in the day. Is there really any difference?
Old British touring. 72 square 50 to 55 mm fork rake, 43 cm + chainstays, 57 x 57.
57 cm Hilson: 72 square, 52 cm rake, 45 cm stay, 57 x 57
Hmmm. Nothing new under the sun. Except for fitting perhaps 1 size large to get the bars up and back.
I imagine I could ride a Hilson loaded with bags no hands on the level and put on a jacket.
What would I get from their line?
Looking at geometry, Legolas in 55 appeals. 73 x 72.5, 55 x 55.5, 45 mm rake, 43 cm stay. Quickbeam 56 is a bit slacker in the seat, low and long rear end. That's cool, too. Most of them seem to have reasonable geometry for smooth handling road bikes.
I think the big deal is the way big sizing. Everything else looks like standard dated road bike design - which doesn't feel nearly as dated on the road!
This is fun now. Let's see what they would want to put me on. Two types of riding. First, fast recreational with smooth handling, lots of hills, light loads at the most. Second, mid-weight short tours, commuting, utility. 170 lb for me, 30 for the bike on the first one. Add 30 for the second. So 200 to 230 lbs. Looks like they'd put me on a Hilson. I'll look at it. I like. Wonder if my old Campy sidepulls would fit.
OK, much discussion about very pedestrian, well thought out bikes with lots of puffing. "Big bike = comfortable" - funny, I used to tell people that in 1973 when I was selling bikes! Old stuff in new package. I'd probably compromise and go slightly big, but below rivbike's recommendations.
Would be quite a contrast with my tiny carbon compact, which is very dinky and tight and very Italian, with my bars and saddle out from the center, wheels tucked under. That one screams GO GO GO GO GO all the time. A mellower ride might be fun.