I really struggle to understand why people still use Twitter. Every time I mention my frustrations with Twitter someone will get defensive, or try to "help" resolve my particular complaint. Those who get defensive try to explain why Twitter is the place you have to be, and those who try to resolve my issues invariably are using some workaround to overcome an acknowledged shortcoming. I will admit this now. I am going to try to convince you that you don't have to be on Twitter and that Google+ doesn't require all the workarounds Twitter does.
If you've ever defended Twitter, you have heard this before. 140 characters is too limited. It is sometimes possible to express a thought in such a limited way, but when it's not enough (which is often) you have to spend time figuring out how to make it fit. Do you go back and edit the phrasing of the thought or idea? Do you split it into separate tweets? Do you blog it and link to it? There are indeed solutions and workarounds, but no matter the solution, you could have already posted your thought on Google+ and moved on.
Primarily because of the 140 character limit, nearly every tweet includes (or is) a link. Including a link eats into your 140 characters making it difficult to even adequately describe what you're linking to. This has actually enabled spamming and the spread of viruses using hacked Twitter accounts. It's not uncommon to see tweets like "Check this out!" with a link. Given the limited nature of tweets, that could very well be a legitimate tweet, even from someone you trust. If you link to another page in Google+ the default behaviour is to include a small image and text clip from the linked page, which helps you figure out if you want to follow the link or not.
Links in Twitter aren't too bad to deal with on a computer, but on mobile devices the Twitter app has to load up the web browser app. You then have to use whatever multitasking feature exists on your mobile device to switch back to Twitter after checking out the link.
So, the 140 character limit doesn't really exist, but it exists enough for it to be a pain. It doesn't reduce data requirements, because you will need to have Internet access to see what the tweet is really about. If anything, Twitter will cause you to use more data because you will constantly be downloading full web pages. The 140 characters may have worked for SMS forwarding to your phone in the past, but that just isn't realistic any more.
One of my biggest pet peeves with Twitter is conversations. These can take the form of people sending tweets back and forth without using direct messaging (either because they don't know how to DM or are just too lazy to be bothered), or people using hashtags to participate in some twisted form of an online event. This leads to posts that followers have to "figure out". Conversations and events are forced on to the interface, and it shows. Use Google+, and an entire conversation can happen in posts directly under the original post. Events can be (and are) done using a Hangout or Hangout on Air which are well integrated into Google+.
It has been recommended that professionals should create two Twitter accounts. One is used for professional purposes, while the other is used for personal sharing. In Google+ you create Circles, and you choose which circles see each of your posts. The ability to direct posts to specific people or groups of people is integrated in the interface, so you don't have to create multiple accounts. You can make your professional posts public, while keeping your personal posts personal.
I constantly hear that there is more "going on" or "being shared" on Twitter than on Google+. While I do believe that to be somewhat true, there is still a lot happening on Google+. I suspect that some of the perception of Google+ not having as much comes from the built-in ability to be selective as to who sees your posts. On Twitter, people see everything you post, whether they are interested or not. As an example, there are people on Twitter I have followed for their expertise in implementing technology in education. I really don't care about their fitness routine or goals, their preference of vehicle, or any other topic other than educational technology.
The other way to get more out of Google+ is to join Communities. You will see far more posts if you join a Community, and you are more likely to discover interesting people on your own when you see someone sharing good, relevant information on a regular basis to the Community.
One oft-recommended solution to solve Twitters problems and shortcomings is to use 3rd party apps. That is simply ridiculous. I do not have to search for and install apps to get Google+ to do what I want it to do. I don't have to worry about keeping multiple 3rd party apps up to date, or worry that they might get broken by API changes or some "token limit".
So you can keep figuring out ways to make Twitter work, or you can just use Google+.