We've been evaluating Aspose.Tasks for several days now, and I've both positive and negative things to say about it.
THE GOOD:
1) All the folks at Aspose have been professional and responsive every time I've communicated with them. Special thanks go to Alexey Zhilin of the Aspose Tyumen Team for putting in extra effort to answer our may questions.
2) Evaluating Aspose.Tasks exposed us to some of the other Aspose products, and, unless we discover a deal-breaking defect, we'll most likely be purchasing some of those other products in the very near future.
3) The quality of the Aspose.Tasks DLL itself is no longer in question. The developers at Aspose have provided a very rich set of properties and methods for managing almost all aspects of a Microsoft Project plan.
4) The online Aspose.Tasks documentation is about as good as I've ever seen. While it's obvious that the documenation needs to catch up to the product, it's very nice to have all the properties and methods listed so intelligently, and formatted in such a user-friiendly way.
THE NOT SO GOOD:
1) After mucking around for a few days, we discovered that Aspose.Tasks does not at the present time provide any recalculation of time and date task data. 
Honestly, if this had been made clear at the outset, we would probably not have even bothered looking at the product in the first place, as time shifting is the sole reason we have for using MS Project. But the documentation lists Aspose.Tasks as being robust enough that we could do away entirely with MS Project automation calls. However, without the *VERY* necessary CalculateProject and CalculateAll methods exposed via MS Project automation, we have no choice for the time being but to discontinue our evaluation of Aspose.Tasks and revert to using MSP automation, or some other as-of-yet-unknown alternative.
We'll be watching the Aspose.Tasks support boards closely, and will resume our testing when/if time/date recalcuations are made a part of the DLL.
