I'm leaning heavily towards the adder-like end of the spectrum. I've been playing around in Elite Shipyard.
I took a stock adder and assumed the following upgrades stock for the Courier.
1: Upgrade from size 3 fuel tank to size 4 fuel tank (+8 tons of fuel).
2: Upgrade from clas 3E shield generator to class 4E shield generator (+5 tons)
3: Extra hardpoint is equipped with a 1F pulse laser (+2 tons).
A stock Adder burdened with an additional 15 tons of mass has a jump range of 7.81 LY, which is identical to the stock jump range for the courier listed in the Dev update.
This leads me to suspect that a jump optimized Courier will have a jump range similar to an adder. While I would have preferred better jump ranges, I can probably live with Adder equivalent jump-optimized ranges.
It may be possible to optimize the Courier's jump range further if its base hull is actually a 30 ton hull that utilizes the 10 ton 4E thruster instead of the Adder's 35 ton hull with 5 ton 3E thruster. It may be possible to downgrade the Courier's thrusters and achieve a good sized boost in FTL range. For low mass ships like that, any trimmed tonnage adds up to noticeable differences in jump range.
I worked out the exact fuelled mass for the jump range with a 3E FSD, it's 90.8T exactly. Which works for a small ship, as you need a class 1 module with 1.3 tonnes to get an exact fit for that mass.
But that makes it very, very odd - a ship the equivalent of an Adder costing 1.6 million? So a pure vanity ship?
For it to work as a small ship it will need be a tough fighter, able to carry a respectable cargo with a reasonable jump range and be fast and agile to boot. A literal jack of all trades.
This is a really tough ask for a small ship. If Armchair is right about it being a small ship, this is only possible if it's got an extremely light hull mass combined with an oversized fuel tank as he states.
Behold the Imperial Courier! (Small Version) Unfounded wild speculation follows - this is how I'd personally build a ship costing 1.6Mil with a total mass of 90.8T)
Description : Gutamaya's advanced luxury light ship, using state of the art construction techniques it has a ultra light weight hull without compromising structural strength. It's the fastest, best equipped ship in it's class.
Dry mass 74.8T
Hull Mass 25T
Base Speed 277
Boost Speed 400?
Base Shields 60?
Armour 80?
Agility 7?
Ships Systems
4E Power plant (10T)
4E Thrusters (10T)
3E Frame shift (5T)
1E Life Support (1.3T)
3E Power Distro (5T)
2E Sensors (2.5T)
4C Fuel Tank
3x C2 hard points
4x Utility mounts.
Stock Equipment.
2x Small Pulses (4T)
4E Shield Gen (10T)
1E Basic discovery scanner (2T)
Total Equipment weight 44.8T
Total Dry Mass 74.8T
Internals - Guess Based 12T stock cargo (Which implies 8 and 4 stock racks), and that existing multi role ships stock equipment mass tends to closely match there maximum cargo capacity, and that the Adder has 5 internals.
4E (8t Cargo)
4E (4E Shield Gen)
3E (4T Cargo)
2E (Empty)
1E (Basic Discovery)
Total possible cargo 46T.
This configuration would be quite flexible. The flexibility comes from the ability to downgrade all of the components.
It's shielding should outclass a Cobra's thanks to the low hull mass, big power plant, low power overhead and those four utility mounts.
Agility will be on par with the Cobra with two noticeable exceptions, much better acceleration and a very good yaw (Gutamaya style).
You can build a tough, well armed light fighter as there's plenty of power headroom for shielding and weapon load outs - dps is constrained by the C3 distro. With a full combat load out your looking at a 15 LY jump range. The weapon grouping will be tight, even if the 2 hard points are on the nacelles the spread shouldn't be any wider than the Vultures.
You can build a reasonable stripped down explorer with a 25 LY ranges (22 LY with the 16T tank, giving a huge endurance).
You can build a trader the can carry 42T with decent shields that's fast with a laden jump or around 15-16LY. Overall it's not well suited to trading, other than running missions.
What you get is a small agile ship that punches above it's weight class, if still at a vanity pricing. It's a hotrod Adder with a view, a toy for the rich, vain Imperial citizen. A ship that will garner a dedicated fan base.
I guess we'll find out soon enough. I'm not convinced it's a small ship.