In the previous version, a considerable amount of users have filed bug reports that they are no longer be able to load certain apps like Twitter and Facebook, also few of them are stuck at the loading screen before end up crashing. But I am not really sure, whether this version brings fixes for that those bugs too.
But the main reason of Spire 1.0.1-1 is for opening access for Siri to run on external proxy servers with less hassle, to which can benefit developers for experimenting purpose, who knows they manage to come out with porting custom Siri commands.
But some iPhone users prefer not to install this update as there is no additional useful benefit for their jailbroken iPhone. And as for those who have AssistantConnect installed is recommended not to update, as there is a report it stops working after updating to this version. Or may be you have good reason for upgrading, write down on the comment form below then.
And if this is your first time hearing about Spire, Spire is a Cydia tweak and the first legal Siri port on devices older than iPhone 4s like iPod touch 4G, iPhone 4, iPhone 3Gs and iPad. What makes Spire is legal because it downloads Siri files from Apple, however does not break the company term of service.
If you are interested to download and install Spire V1.0.1-1, you need to firstly jailbreak your iPhone 4 running on iOs 5 and then launch Cydia to search the package via BigBoss repository and refresh the source if you wish to update to this version.