HP SmartStream Designer for InDesign CS5 have more imposition features than the Designer for QuarkXPress 8.

For imposition only, you may use HP SmartStream Designer at no charge.
A SW license is required for creation of variable data jobs.

As a member of the HP R&D team that develops the SmartStream Designer - we are certainly one team - and we do talk with each other 

You may try the Designer for QuarkXPress 8.5 - we improved there some look & feel, so it is closer to Designer for inDesign, but indeed, almost all new features go to the Designer for InDesign.

I know some other companies that used to do plug-ins for both products stopped the development for Quark.
The Designer for Quark is primarily on maintenance/compatability mode, to enable you to continue working with latest QuarkXPress 7 & 8, while most of the new features we develop go to the Designer for InDesign CS5.

That's the reason for the functionality differences you observed.

As for the upgrade price - Search for the order form in the My-HP-Indigo web page.

The Indigo YoursTruly Xtension is now named HP SmartStream Designer.

HP SmartStream Designer for InDesign CS4 & CS5, and SmartStream Designer for QuarkXPress 8 installers are available for download at
www.hp.com/go/SmartStreamDesigner
or at 'My HP Indigo' web pages.

HP recently released SmartStream Designer for QuarkXPress 8.5, which is including fixes to few reported issues since 8.0 was released.

You can do such effects with SmartStream Designer, using one of the Dynamic Personalization integrations.
The Dynamic Personalization enable activating Photoshop, or one of DirectSmile solutions - DirectSmile Creator Pro, DirectSmile VDP Studio or DirectSmile Online, from SmartStream Designer.

Photoshop enable the Photoshop experts design a nice PSD template, and then, change text, images or layers in the PSD via SmartStream Designer, according to the database fields that were imported to Designer.

DirectSmile software enable to use any of your DirectSmile templates (dsets, or dopr) as an image channel in a SmartStream Designer job. Again, the text in the DirectSmile template would change according to the database fields that were imported to Designer.

With SmartStream Designer, you can output JLYT, PPML or PDF/VT

There are two ways to do barcodes with SmartStream Designer:
-          Barcode fonts
-          Barcode images

Barcode fonts:

It's possible to do Intelligent Mail Barcode SNAP via ID-Automation fonts. When using IDAutomation's Intelligent Mail Barcode Fonts, a font tool must be used to generate the text string for the Intelligent Mail barcode font because of the complex encoding algorithms used in this symbology. This generated string will create a correct barcode when combined with the IDAutomation Postnet Font.

Example: ID-Automation font tool will generated from a data string of 0123456709498765432101234567891, the following encoded characters string is generated:
qqrspprpsrqrsqqrqqsprsrrqqqrrsrssrqpqrqrrrsppprrsssqrpqqqrpsrqqrq

The database must include the converted encoded strings, not the original digits.

This workflow is the fastest, however, more complex, as it requires an additional step to convert the barcode values to encoded strings.

 

Barcode images:

Intelligent Mail Barcodes may also be created dynamically with image Channel's Dynamic Personalization option, e.g. with TEC-IT Barcode Studio.

The Intelligent Mail Barcode is also known as "USPS OneCode 4-State Customer Barcode" (BCStudio: USPS OneCode 4-CB). Additional information about this (and also all other barcodes supported by Barcode Studio can be found find in the Barcode Reference:
http://www.tec-it.com/download/PDF/Barcode_Reference_EN.pdf page 46,  - section 6.1.83 USPS OneCode 4-State Customer Barcode

Dynamic personalization barcode images will work in all output formats, except in JLYT-Template mode.

This method is the simplest to use, as the database include the original numbers, and no conversion is needed, but cannot be used in JLYT-Template mode.