I'm eyeing up the Coasts to Castles route as a future ride and thinking I probably ought to change my 25mm slicks for something with a bit more comfort and grip. These two look good options, though I think maybe the Almanzo tread pattern might be better, but I'm not sure if I'll have clearance for 33mm. The Strada Bianca should fit but might not be grippy enough? Anyone using Challenge tyres - are they any good? http://www.challengetech.it/products/gravel/strada-bianca-pro-040/en http://www.challengetech.it/products/gravel/almanzo-pro-041/en Other options under consideration are Vittoria Tereno Dry, Schwalbe G Ones and Panaracer Gravel Kings. Any thoughts & suggestions welcome. Cheers.