I've thrown this rod in both the 490 and the 590. I love both.
I'd say either of these weight rods can be used as a go to, multipurpose rod. It just depends on the size of the river you fish as to which you need. The 490 is going to throw lighter tippets and drys a bit easier, and the 590 can handle bigger bounce rigs and streamers a bit more easily. Honestly if you can afford both I'd suggest it. If you try different fishing strategies, and fish different rivers instead of just doing the same thing at the same place all the time you'll find a use for both.
At the same time either can be your go to all purpose rod. I've used the 490 on big rivers, and the 590 on small.
The best thing about this rod series is the feel you get along with the speed. I read a lot of reviews and comments about this rod and of the ones that weren't fans of it, the most common complaint was it felt like a baseball bat. I disagree completely. These rods have a great feel and give you an almost telepathic sense of where your line is and where its going through the entire cast. That I think is its best attribute. I get less snags in tight quarters as a result of this, and that's just the ancillary benefit. The other benefit is my casts land where I want them to, and we all know this can result in more fish being caught... I stress the "can" here.
All in all I think this is a fantastic fly rod. One that I'll definitely keep for a long long time. I'll hopefully pass it on to my kids some day.