Default [Q] Update from old Omni ROM

My WiFi Xoom is currently using Omni 4.4.2-20140427-1908+0200-wingray-HOMEMADE and kernel I would like to update it to a more recent version of Omni ROM. When I first installed this ROM, everything worked very well. However, in the last few weeks the Xoom has frozen every few days. Launcher 3 also fails from time to time. This may or may not have anything to do with the ROM, but I might as well bring it up to date.

In Settings/About Tablet/System updates, I am being offered Do I just "Flash now" from this update page, or are there other things that I should do, e.g. do I need to update gapps. If there are other things, what order should I do these in?

Most of the update information I have seen relates to updating a non-BigPart Xoom, but mine is already set up with BigPart.

Any help would be appreciated.

Thank you