Well, as is tradition, I bought a new Royal pro series and then immediately found a gorgeous 5700 for sale on Craigslist...  I'm not sure if that is lucky or unlucky... 

Why did I buy the Pro Series (UR38200) rather than a commercial version?  If you go to Royal's website, the Pro is pictured with a headlight and, presumably, a scent chamber.  All the online dealers (including my favorite, www.ecovacuum.com/1.html...) use the same photo.  So, I was willing to lose an Amp of power for that and the stylish black and silver coloring.  Well...  They no longer make any metal royals with headlights and such.  It's an old picture.  I even called Royal and their support staff went digging through schematics and part lists.  They finally found one that had bold letters (which surprised the phone agent) saying HEADLIGHTS ARE NO LONGER AVAILABLE.  The manual has a date code of 2012 and does not show a headlight...so the photo must be very old.

The pro series is a nice vacuum, but the fit and finish are noticeably cheaper than the older 5700.  Many cost cutting measures have been taken, including a lack of light, scent chamber, handle support spring, no infinite height adjustment, and other minor differences.  The polish job is strikingly poor on the Pro in comparison, even if they were going for a slightly matte look.  The Pro is heavier and has more weight to the front, so it droops when you pick it up (if the handle is unlocked).  The 5700 is nicely balanced.  

The 5700 has some speckling to it's finish, but is otherwise magnificent.  I know a Kirby repair man who can work his magic on it I'm sure.  It needs a new belt, so I ordered the older style belts for it.  It also has a bush roll indicator light!  The brush strips are in really good shape.  It was hardly used!

To oil the 5700, do you just pull the red plug off of the back and use some motor oil?

Enjoy!   

I had read that the 7 Amp Royals used a different belt than the later ones. 

Wow, it was actually a quote from you from 2014!
"Dependent on the motor size, Royal has produced three different belts over the years: if one of your machines is less than 4.5 amps, use only the soft belt 1043260001; if between 4.5 and 7 amps, use the flat belt 1044260001; if the machine uses a hex-ended brush roll, go for knurled belt 1672260001."

www.vacuumland.org/cgi-bi...

The belt it came with seemed different from the one on my pro series, so I ordered the 1044260001.

I imagine the toe touch on the pro series is pretty reliable since it is only a 5-position system.

It's cool that you live somewhat close to me!  Find any good vacs out in the valley?

Yah, I know!  I would have gotten the commercial 10 amp if I had known.  The black and silver is great looking though.

Nice!  I love the look of old Kirby's and Bell-type vacuums.

According to this old dealer VHS:

Some models could lay the handle all the way back and lock so you could store the vacuum on its face.  Which models of Royal did that?  The 5700 doesn't seem ot have that feature.  Not that I would want to put all the weight on the headlight cover.

Nicholas,

 I have the Royal 8300 made in 2008. The 8300 has a headlight and the handle latch allows the handle to be locked in the horizontal position which allows the machine to be stored in the vertical position such as in a broom closet taking up very little space. The weight of the machine rests completely on the front bumper and not on the headlight cover. The headlight cover does not touch the floor at all.

Between the two, the 5700 is a better machine to use.  Lower weight, better balance, and quieter.  It's a decked out Lincoln Town Car vs. a P71 Crown Victoria.  The Pro Series is a more powerful machine, but rougher around the edges.  It really comes down to personal taste and goals.  If you want a deeper clean, the Pro Series is going to do better.  But, both are great machines and I would recommend the current Royals for people who want a solid and reasonably priced vacuum.  It is a shame that the accessory kits have been discontinued though.