I have the LMS 3990 and have added a number of upgrades including the power feed, tach & inch-leadscrews and I changed out the locking levers for the three axises to make them a little more user friendly (DRO parts are here, just haven't gotten around to installing them). In hindsight, I would go for the 4190, which is the deluxe version of the 3990, with DRO's and the interlocked spindle lock already installed: the extra money is well spent since the DRO package has more capabilities than the self-installed version I will end up with (still adequate for my needs). Overall, I am very happy with the 3990's performance and capabilities
If I had more space, more money and a shop not in the basement, I would go for the LMS 6550 bench mill (or a similar PM). However, the combination of footprint and weight would make it difficult to get in my shop - it was a struggle moving the 3990 into place.
