You can use JSW CRM 5 as a CCK in Joomla 3,4 & Joomla 5.

CCK like K2 but different

It has. in comparison to, some more features than K2 & it is missing some.

JSW CRM is made for easy creating & managing pages in a joomla 3, 4 or 5 CMS with lots of possibilities to set the layout of a page, what you want to see on a listpage for example, where the image is set in opposite of the text & how large it is showed.

Besides this we have focused on seo stuff, every page has seo properties, what's the subject?.

You can set the seo on category level & you can override it if a page of the category has another SEO goal.
The fields that a certain seo properties needs to make it properly index that way, are added in the edits screen of that page, so it should be easier to make pages that score in the searchengines..

Some of the properties of K2 are also built in JSW CRM

• A new page only needs the title The rest is optional.
• What you see on which layout you choose at menulevel can be set.
• There are extra fields, but it works a bit different. Every page can be provided with a call to action button & some extra fields, Most of them show up when you select a certain seo property.
• JSW CRM manages his own images & files, just like K2.
• JSW CRM creates a thumbnail of a large image you upload automatically, just like K2 does, only 1 format though, This image is used for all available layouts of a page. Works fine..
• JSW CRM 4 has a image gallery tool added to it just like K2, But it needs one or more extra tools, just like K2..
  There are several ways to make this work the way you like in JSW CRM 4

The main features that makes K2 so popular are there, JSW CRM has a few awesome things added to it that K2 does not have.
Here's a small list of what we came up with:

• Of course JSW CRM 5 works on Joomla 3,4 & Joomla 5, so migrating should not be a problem
• JSW CRM 5 can handle (very) large files that can be added to a page as download
• A JSW CRM 5 (item)page has a contactdata collection added to it you can use
• You can add a location & map to a page. This needs a Google or Mapbox account. 
• It has several modules & plugins to do stuff with JSW CRM on the normal article pages of Joomla.
• With a few clicks you can export all the data in the database to a csv zipfile
• You can export a selection of items as csv you select in the admin
• It has a first class full responsive interface front end & back end of the website
• It's no problem to manage your website items from the front end with JSW CRM 4
• It has extended possibilities on the user rights level. It even has more possibilities to set the rights of items & users than the joomla core
• JSW CRM 5 can manage video's & other media very easy, even streaming video's or other media from your own server is not a problem
• JSW CRM 5 can connect to cloud files from providers like Google, Microsoft, Dropbox. Making a cloud file available in a item, just copy the link..

We are making some example pages made with JSW CRM 5 available here soon, so you can see what's possible...