.NET, WPF, which version of .NET to choose - 3.0 or 3.5

Question

.NET

Hello!

The situation is the following. We have a fairly popular (non-Enterprise) end user program written in WinForms and .NET 2.0. At one time, they chose 2.0 to cover as many users as possible.

Now we are planning to develop a new version. I would like to make a beautiful and unusual design, so it will not be very convenient to stay within WinForms, and we are considering switching to WPF.

We have the following data on users:
85-90% already have .NET 3.0 installed
60-65% already have .NET 3.5 installed

It would be ideal to stop at .NET 3.0, and not force users to download 200+ megabytes when installing the program ( traffic is still a problem for some).

Moving on to questions

1. How is the implementation of WPF in .NET 3.0 different from .NET 3.5?
2. Has anything new/necessary/convenient been added in 3.5?
3. Are there any critical/unexpected defects in WPF 3.0 that you should be aware of?
4. What would you choose if you were in our place?

Thanks in advance!

Answer 1

1-2 Nothing interesting.
3 Blurred fonts, fixed in 4.0.
4 If the format allows, silverlight, otherwise WPF 4 client profile ~ 30 mb.

Answer 2

Choose 4.0.

Answer 3

I support the previous speaker and strongly recommend looking towards version 4.
It has better performance, a blurry text issue (which is very important for users), and some other useful things, such as Easing Functions, which make animation much "tastier".
Include the framework in your installation package, is 40 mb a lot?

Answer 4

I fully agree with the previous 2 posts. You need to immediately transfer users to a new framework, so that it does not work out like with IE6.

Answer 5

I join those who campaign for 4.0. I recently started a new project on the quartet with WPF. Some positive impressions. True, before that I did not write anything in .NET. It went very easily, despite the fact that this is video recording and processing. Here the merit is not really .NET, but OpenSource libraries and previous experience in this area. But as far as the user interface is concerned, it's a solid sugar, which, however, is sometimes difficult to obtain. In the sense that everything is very flexible and not always obvious, but when you do it, everything becomes obvious and logical.
For example, I made an asynchronous filling of the ListView with data in several threads in just half an hour, of which most of the time is googling .search WPF and .NET help. With the previous tool, this would take a day or two. And a lot more code.