It is certainly very convenient, when it works. It feels kinda strange to trust every financial detail of my life to the government, so whether it is good in a real sense is a question I'm very open to debate.
It does allow some very useful applications to be developed, with a very nice potential for streamlining interaction between government, citizens and private sector. This is actually very high on the government's agenda, which I'm happy about, because the bureaucracy is sometimes both heavy and heavy handed.
If it is done well, it could potentially enable citizens to simulate possible choices in their lives before they make a decision: "If I do $that, the taxes will be $this". It would also enable an improved public debate: now it is a lot of bickering of the style "if you raise $that_tax, it will adversly effect $that_group" "no, it won't, but not doing it is required by $that_group". They're just making things up, of course, the debate is usually completely devoid of facts. Soon, it might be possible to simulate those scenarios on a regular basis, so we get real facts on the table before making a decision.
Unfortunately, there's a long way from good ideas to actual implementations. I've been in meetings with the people who actually order these systems, and what can I say... Heads gotta roll to go anywhere... They're easily blinded by suits, and they have no idea what makes a robust system. So, for now, I'm not too confident it will happen, even though there are some very interesting ideas around.