I have a Classic Series from 2 years ago and a Sig from last year. The older Classic gloves had a thick leather and seemed heavier than other gloves of the same size. The colors also faded rather quickly. 44 has replaced this line with the C2 series, but I haven't seen one in person to make a comparison. From pictures, however, it seems like the C2 has a tighter grain in the leather.
The sigs have much better leather (kip) and really are an awesome value especially considering how much customization is available. A buddy and I both gamed 11.5" I-Web sigs last year, and we both noticed the length of the actual I web is rather big compared to my HOH Pro-202's I Web. If we didn't keep the web totally tight against the tumb and index finger, a baseball could fit through it. I haven't seen any reviews that mention this issue as well, so maybe it's a one-off. The sigs come pretty stiff, so they do require a little love before playable.
The lace quality is good- definitely not Tanners, but better than Wilson.
Their customer service is fantastic.
These are just my opinions, of course.