The wheel is gone, but you certainly can micromanage the building of items on each colony. There's no longer control of the per planet economy/production rates (science vs economy vs production). At this point, the main slider under "Civilization" basically controls income vs unhappiness for all planets.

The new concept is that you pick a point of taxation that produces an empire wide level of happiness (or unhappiness) and a resulting net income that is useful to your strategy.

Thus, the point is now to keep your citizens as happy as possible, so that you can set the tax as high as possible without having them revolt. If you can keep everyone at 100% and still make a profit, you get massive bonuses to growth and production. Usually that isn't is possible and then you look for ways to income the income of your empire.

What's nice about this mode is that when you do specialize a planet for production or science by building certain improvements, none of the other production type is "wasted". Income generation is the only part that is now limited, and that's only limited by your overall tax rate.

Pro Tip- production rates are now based on the "raw production" of the colony, and science, income and social/ship production all have that as the base value. If you can increase the raw production, everything goes up by that base amount. Most improvements are now just percentage increases on the base production for their area. but a few add base production for their areas.

pop is in now 1 for +1 raw

asteroid mining is +1 raw  per mined asteroid within 10 hexes (further distance drops the production)

Cities and capitals now accept adjacent production improvements as +1 raw for the colony

With the right set of population, improvements and asteroid mining, it's possible to get over 100 production from a planet, and that's potentially for all 3 areas of income, science and general production. A base planet early game might just 3-5 production.

It's not the same, but it's nicer in many ways. I always hated throwing away the production or science on a planet that was micro'd to focus on something else.

Ah, look at the upper right corner of the civilization screen and watch the overall happiness indicator to see the immediate effects of the taxation slider.

the planet values, in the planet bar at the top-right, don't update properly.  The numerical percent at the very top-right does.  You can update planet values by clicking on another tab, then back to the colony tab.  They should have this fixed, it has been mentioned many times.  

You can also add to any one of the production areas mentioned by assigning Citizens with the desired specialization to the planet. Put it in the Empire area for a global 3% increase or on a specific planet for a local 30% increase.