What seems to be rarely mentioned about manual mill choices in most threads is that while a Bridgeport or the same sized clones aren't the very best in absolute rigidity, they are so common because of there versatility. To me you can't look at any mill as just a machine tool. Depending on what your future wants and requirements might be, there's few other mill types that can do all that much more than straight X,Y,Z vertical milling compared to the BP design. I'm not including the European Deckels and others like them that I'd still rather have. But if the job could be accomplished at all on a 2200 lb sized mill, then there was an accessory made for those Bridgeport dimensions. That ram dovetail way, Bridgeport's and clones 3 3/8" spindle nose diameter, R8 taper and a few other critical areas on the head and ram allows all those various attachments to be used as a direct fit without any modifications. That R8 spindle taper is now almost a light weight antique compared to the better 30,40,50 tapers, but if it's not available in R8 you probably don't need it. In a commercial shop there requirements are of course different but that's not you so a few more lighter passes aren't a big deal.
I just bought an as new condition Volstro rotary milling head for my BP clone. That's just one example, but there were a vast number of spindle mounted accessory heads, ram mounted slotting heads, cherrying heads etc,etc. designed around the BP platform.I originally bought my mill because it had the same dimensions and features as a real BP. Try adding anything designed for a BP to the square column mills. That might be a whole lot more work than I'd want to bother with. I also wouldn't consider any mill that didn't have the built in 3 spd power feeds on the spindle. Yes there's a couple of square column mills that offer it, but at the same price of the smaller BP clone knee mills are. Most BP clones either come with those spindle feeds or it's an optional head. The built in variable speed would probably be nice, but with my step pulley and vfd in a home shop I don't think it's really worth the extra or the possibility of having maybe a few more future maintenance issues if it uses the plastic bushings the real BP's do. I wouldn't ever trade what I bought for any square column off shore machine. Of course I wish I had a 40 taper 10"x50" 3500 lb+ vertical mill. I didn't want to pay what that would have cost, nor do I have the extra shop room. A home shop just about demands the type of versatility the manual knee mills come with. For whatever my opinion is worth, there's about three real choices. A real BP, a clone of one, or one of those Deckel/Euro type mills. I've had my mill for over 10 years now and I'd still buy the exact same machine today.
Mine because of my shop size and restricted floor weight requirements is what's known as a baby BP or 3/4 sized. It still came with the full sized head for me to get those spindle feeds. Mine was built in Taiwan by a company called Bemato. I don't think there still making this size of mill since there now building some pretty large vertical, bed mills and cnc. But someone is, this is either an exact or extremely close copy of what I bought.
https://www.precisionmatthews.com/shop/pm-935ts-tv/ Ok it's not a real BP, but when new mine had the exact same back lash numbers on the feed screws that BP themselves guarantee. It was tight, fairly well finished with accurately ground surfaces, and it's been more than I could have hoped for. Yes you said you have an area of 30"x30 and didn't want a knee mill, move something, knock a wall out and do what you have to to fit one in.
