You may want to ask your doctor about Uloric (febuxostat). I plan to do so, if my SUA is not <6 by year-end.
Summary of clinical trial comparing febuxostat to allopurinol is here. As best I can tell - but I am NOT a medical professional - the summary says that febuxostat 80 mg/day is more effective than allopurinol 300 mg/day, in terms of % of patients reaching SUA <6, and equivalent in safety, including liver enzyme signals. I don't know of any trials comparing febuxostat to 600 mg/day allopurinol.
Arthritis Research & Therapy | Full text | The urate-lowering efficacy and safety of febuxostat in the treatment of the hyperuricemia of gout: the CONFIRMS trial