I've heard people say these things don't drive 175W lamps properly... So that makes me less inclined to use these for 175Watters.... BUT I do like how small the ballast is, Makes it easier to build around..... I've heard people say these can drive 125Watt mercury lamps at spec, is this true? Is there any other lamps these regent ballasts can drive properly?? I'd like to use the thing, if at all possible... But I just don't think I trust it with my 175Watters...

There isn't direct relation between the ballast size and it's output power (into the rated lamp), but there is quite significant relation between it's size and it's losses. So, a small looking 175W ballast could actually be 175W, but run very hot