You dont have a lot of choice in pure road tires for the 21/90/90 front - I have only seen the Metzler Me 33 in Oz , and it has been around for 30 years.
Most of the Scorpion/ Tourance/ Annekey types are acceptable on bitumen , but here in Oz we have to pay almost the same price for a set we pay for Pilot Powers etc.
And if you push the old girl along the fronts dont last long - 6/7000 km and they are scalloped out and feel horrible
We can get Mitas E08s here in Oz at a sensible price, less than half the others, and I prefer them to the others anyway , so the price is just a bonus.
Plenty of grip , wet or dry, and they have a nice rounded profile on the front whIch gives a turn in that suits my style of riding. Back holds its shape well too, as it wears.
The low price lets me change the fronts as soon as they start to go off- I spend too much on my bikes in a year to try and squeeze another $ 20 - of wear out of a worn tire .
The new Conti Attacks look like they have more rubber and less grooves than any of the above , so lets hope that a new tire with current technology and more rubber on on the road ends up a better road tire - it would be sad if it didnt.