If you tapper up( from one tab and maybe up to 5-6 per day), do lots of low intense cardio I think it's a lot better than T3, for me anyway. I feel pumped, increased strength etc and this I do NOT feel with T3. T3 makes me too flat even when on a very low dose as 25mcg.
Spiropent clen is better than t-3 for cutting you sure as hell feel alot better on it. Oxyflux clen somewhat sucks as compared to spiropent. Also a good portion of pills sold as clen is either fake or eph tabs. If you get spiropent and work your way up to six tabs a day, unless your very fat you will be ripped in a month provided that you moderate calories as well.
If you already have a high metabolism I would not go with T3/clen without gear. If you have a very slow metabolism the two might work for a short period, but for longer periods I think it will eat into you muscles. I would rather do only Clen and just up on the cardio and lower calories.