I have a 280 in .22 and a 34 in each calibre. All full length rifles. The 34 is only very slightly larger than the 280 in overall size. Both handle very nicely and feel similar in that respect. Remember the 280 has fibre optic sights.
The firing cycle is different, due to the different stroke lengths. Not at all sure what I prefer. Like them both. I think the 34 suits .177 cal very well. All of mine are mild mannered but I've read the 280 carbine can be less so in .177.
All of mine seem well built, with good bluing and with none of the faults described above. You may well find it devoid or short of factory lubrication, though.
I think you would be happy with either model, although the 34 Premium undoubtedly looks to best.