There a professional design programs to run the numbers for you, but it'll be somewhat more heat than you're able to get through the sub-floor & finish floor above. The subfloor + finish floor puts about R1-R1.5 between the insulated cavity and room above, whereas with radiant ceiling you only have ~ R0.5-R0.75 between the warmed cavity and the room. Half the R-value delivers twice the heat flux when all else is equal...
...but it isn't quite equal.
Reducing the amount of tubing by half doesn't cut the heat transfer by anything close to half, but the lower R-value of the gypsum is also somewhat offset by the lower amount of convective transfer at the gypsum-room interface as compared to what happens with a radiant floor, where the boundary layer of warmed air is constantly being displaced by cooler air sinking to the floor due to it's higher density. Most of this activity is happening at shin-level, though larger currents down glazed walls usually add some whole-room convection component.
In very rough term half the tubing in a ceiling radiant suspended-tube would deliver at least 1/2 to 2/3 what the upper suspended tube is delivering to the first floor per square foot of ceiling or floor, and if there are rugs or furniture etc upthe radiant ceiling may exceed the total heat flux of the first floor. This isn't a simple thing to model with 3 equations in pencil on a napkin. But you probably don't need to.
If the radiant floor above has been keeping up with it's calculated heat load at the water temp & flows you've been running, it has also been dumping as much as 1/3 of it's heat into the room below despite the foil insulation, so it's actually 30-50% or more overdesigned. Unless the basement room below has a much higher heat loss than the first floor room (not likely, but not unheard of) half the tubing in a ceiling radiant should be able to keep up. If your heat load calc comes in at something around half the BTU/square foot numbers (which it might, with minimal glazing and not much above-grade wall) it'll be at least as overdesigned as the radiant floor was. Odds are you have fewer obstructions to the ceiling too. (Have any furniture/rugs/cabinets/pets glued up there?
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FWIW: You may already know this, but if you can lower the system water temps even 10F and still deliver the heat it'll save ~3% in fuel use. If you can lower them 20F it'll save ~5-6%. At 140F
RETURN water from radiation and below you'd have to design in some return-water temperature safety if you have an oil boiler, but even down to 130F return water you can usually get away with it with gas cast iron, provided you have a condensing-tolerant flue liner. On cold-starts the heat exchangers will always be cold, but you want to ensure that oil HX reliably run above 140F, and gas above 130F for most of the burn to avoid damage to the boiler. 160F is/was a common design temp for baseboard radiation, but is on the high side for radiant in many/most applications (unless your outdoor design temp is -20F or something.) If you can get away with less, it'll usually pay off. Mixing valves, circulators & other controls that run a programmable temperature ramp based on outdoor temperature are available too, so you can run higher duty-cycle/lower temp water, which is easier on things in general, and more comfortable. (google "outdoor reset" )