As you've noted CEON Advanced Shipper has been around for quite awhile and was developed by an experienced and well respected author (may he rest in peace). DropShip Core has not been around nearly as long (First non-public versions were around Jan 2012).
The aim of the two are a little different... The goals of DropShip Core when the project started was 1) Dimensional and Weight Support, 2) Drop Shipment support, 3) Additional Package Support, 4) Freight Support, 5) Making development of Shipping modules supporting the 1-4 easier.
I'm actively using DropShip Core to provide shipping quotes for both UPS Parcel and Freight. The quotes include dimensional and weight based pricing when dimensional data is added for the products / packages. I am using a slightly modified version of the included UPS XML Parcel shipping method and a custom written Freight Carrier shipping module.
While not complete lists, these are a "quick" comparison between the two based upon my experience with the two modules. Hopefully others can add some additional insights.
DropShip Core
- Open Source
- Product / Manufacturer based shipping methods (also based upon origin locations).
- Uses "Zone / Region" defined by the shipping module.
- Rates are determined solely by the shipping module.
- Package Support (Package Types): Can specify package types, dimensions, and weight. Adds products to a package based upon configured rules. See the DropShip Core thread for details.
- Surcharges/Discounts: Handled by the shipping modules.
- Method Availability Scheduling: Only if coded into the shipping module.
- Method Title + Description: Handled by the shipping modules.
- Full Tax Support
- Requires one to create new shipping modules (or modify existing modules). Comes with an example UPS XML shipping module.
- Admin Configuration: Basic, Embedded into Zen Cart admin pages (mfg, product) and some new pages for packaging types and drop shipment origin location data.
- Freight Support: Includes support for freight classes (customer selected accessorials can be added with a separate module).
- Base Classes for developing additional shipping modules supporting Dimensional and Weight based shipping, drop shipments, etc.
- Can optionally save quote request and response for the selected shipping method.
CEON Advanced Shipper
- Commercial
- Product / Category / Manufacturer based shipping methods (version 5.0.0 lets you specify a origin location per shipping rule).
- Can set custom "Zone / Region" in Advanced Shipper rules (some configurations may require another module from CEON).
- Rates are determined by the shipping module + Advanced Shipper configured shipping rules.
- Package Support: Based upon maximum package weight only.
- Surcharges/Discounts: Handled by the shipping module + Advanced Shipper configured shipping rules.
- Method Availability Scheduling: Shipping module + Advanced Shipper configured shipping rules.
- Method Title + Description: Handled by the shipping modules + Advanced Shipper configured shipping rules.
- Full Tax Support
- Works with most Zen Cart shipping modules.
- Admin Configuration: Well written, easy to use, separate from existing admin pages.
- Freight Support: none.
I would choose the module to use based upon your store's needs. In some cases CEON Advanced Shipper may be the best choice, in others DropShip Core may be the best choice.
Disclaimer: I am the author of DropShip Core.
The CEON website still has a demo running under Zen Cart 1.3 if you want to check it out before buying. DropShip Core does not have a demo website, but you can download and install it on a test site to check it out (I would also recommend reading the two PDF's in the DropShip Core thread).