Strong rumours that new Garmin Edge 540, 840 & 1040 devices will be released in the next month (or two, early June is firming as likely), the x30s were released 3 years ago so technology has moved on a little, much speculation but no details, keep an eye on DC Rainmaker reviews perhaps, my "maturing" eyes are gravitating towards the bigger screen model (ie 1030) but they are oh so expensive. If the x40s have nothing new to tempt you then at least the x30s will be discounted to clear old stock.
I have a 530 (and have had 200, 510, 520 in last decade), the 530 has a very clear but fairly small screen and has great battery life, I can get over 40 hours without too much feature compromises. With hindsight I would buy the touch screen user interface models (830,1030) rather than 530s button UI. The Garmins have been let down a bit in recent years by poor software, the developers ( or their managers) just don't seem to understand what makes a good cycling device and have lost the art of testing. Stay tuned I guess.
If like me and you don't use 80% of the features it takes a little digging to turn off the unused stuff so it doesn't annoy you for years to come but worth it.