problematic, tricky, troublesome, complicated, difficult, advantageous, dicey, useful, inconvenient, interesting, unpalatable, costly, troubling, preferable, confusing, beneficial, perilous, intriguing, perplexing, important, uncomfortable, dangerous, touchy, disconcerting, expensive, desirable, daunting, contentious, prohibitive, helpful, fascinating, vexing, plausible, worthwhile, feasible, unpopular, debatable, instructive, unadvisable, onerous, untenable, tricksy, inadvisable, nettlesome, counterproductive, frustrating, impractical, irrelevant, felicitous, cumbersome, puzzling, unpromising, superfluous, amenable, paradoxical, dissimilar, unproblematic, sticky wicket, unappealing, germane, disadvantageous, murkier, apt, risky, unreliable, precarious, irresolvable, inviable, thornier, crucial, irksome, unfeasible, unimportant, unlikely, infeasible, unavoidable, unsuited, unsettling, awkward, propitious, inapt, baffling, disorienting, convoluted, iffy, undesirable, unworkable, worrisome, uneconomical, tiresome, stickier, improvable, tenuous, fortuitous, palatable, unstable, unpropitious, tedious, disenchanting, bothersome, peculiar, uncongenial, doubtful, mystifying, analogous, disputable, undefined, ambiguous, uncontroversial, determinate, equivocal, unsatisfying

hard, knotty, questionable