I think I may have mashed out two or three beers in the few years I've been brewing. I don't have a problem with any of my non-mashout beers being too thin <unless a very dry beer was my intention>. Whether your beer will be dry or not will probably have more to do with your mash procedure than the absence of a mashout.
The lower viscosity that you get during a mashout is due to the higher temps only. I.E. - temporary. IME, your overall wort viscosity is no different at fermentation temps whether you mash out or not. So, there should be no affect to the final beer.