Just set the 1/4 round on the floor without any cement, and see how you like it. Depending on your personal taste and the style of your bathroom, you may or may not like it. At least you'll have a better idea how it strikes you within the context of the room. Personally, if it were my bathroom, I would hammer out the adjacent tiles and re-tile it up to the tub. Stuff that I've worked on around the house that I'm not happy with aesthetically just ends up annoying me to no end. I've redone a couple of projects in my house just because I didn't like the way it looked in the end.

Cold-weather... thank you for your thoughful response. I have some comments and questions for clarification, if you don't mind: If you’re thinking of raising the deck, a deck-cabinet gap can be concealed far easier than the tub-deck gap, but the deck is hard in the wall tile, so that's a big bite for the tile installer to eat. >>> You are sooo right about the tile on the deck being against the wall and since the bottom has crackled glass tiles you can't raise the deck tile without it coming against that glass... and that you can't replace just one row of the glass without it messing everything else up. Darn!!! Guess that option is out.Any tub installer who left it that way is a screw up. The tub installer was the ONLY person who was in a position to fix this thing. Since that person did not, that person gets the prize for the ultimate screw up. If he/she could not do a better job, he/she should not have done any job. The entire onus is on the tub guy to do it or to not do it. >>> The really frustrating part is that I have been a part of the process - trying to get them to do it right (I had to tell then that they used the wrong material - drywall instead of mortar... and I only found that out by researching and talking to people). The GC wanted to give them another chance to fix the issue and since it was only putting mortar in, we didn't think they could screw that up (wrong!!!). Now we have a mess. That's a fiberglass/plastic tub with two things to be aware of. One, the feet can be cut, and they can be set in a bed of mud along with the tub belly. They’re wood blocks covered with resin. Two, the top can be scribed, but only by someone far more competent than this guy. That tub should hang by the top rim and sit firmly on the bottom mud at the same time. It should be set in the mud (which could have a separator layer like a plastic bag or a piece of shower liner) with a load of water in it. >>> Unfortunately it is near impossible to get to the back right corner of the tub because it is filled with all kinds of innerworkings of the tub. The good news is that the ONLY corner that lays flat against the tile is that back right corner... so presumably they can work on the other 3 corners. The mortar does have plastic on it now... so I guess that's a good thing.. would they have to take all the mortar out first and then do something with the feet? By scribing do you mean shaving the top of the feet off? (I hate to say this but in the framer took off a couple of the back feet off at one point... because he thought they were part of the shipping material.. not supposed to stay on the tub). And by mud with water... do you mean mortar like shown in the pic? Caulking/sealing/bridging a quarter inch gap is absurd. The sealant is to stop water from seeping, not to stop pencils from rolling. Sealant thickness should be nearly unseen. It has no strength. Cut the tub. Everything points to the tub person being not skilled enough to eat a donut without a bib. Since the top edge of the tub is NOT level, cut! I can’t see how the GC could allow this. >>> Funny that you should mention pencils rolling - I just took a pic tonight to send to the GC and one of the pics showed a pen under the edge. Okay, not funny at all. Thank you for explaining about the sealant and why it has to be fixed. Cut the tub. >>>What do you mean "cut the tub"I'm gathering from everyone that this is a big problem that just has to be fixed.. it's not an aesthetic thing (which is bad enough... that big gap is going to look bad) but I'm going to have a problem down the road...

What do you mean the gap between the tub and the floor? Freestanding tubs usually stand on 4 legs so there is an opening... If your tub model comes with enclosed sides some models have slightly recessed tub's bottom area for the tub to sit on so there will be a small gap under it. It all depending on the tub model but you can see some models have a slight gap between the tile and the tub so if you have a similar gap that is normal. Can you post a picture?

Thanks for all the comments. I ended up getting a nice 13 amp grinder with a concrete grinding wheel. Since about 1/5th of the floor is the hump I opted for the grinding. So far I have taken about 1/4" down. As far as the "pros" and "experts"... this concrete was done by the "pros". The rough framing which I've had to fix in multiple spots was also done by "pros". The HVAC runs that I have had to re-adjust so that sheet rock will fit on the walls was done by "experts". The upstairs tub, which had the overflow leak all over the downstairs ceiling, was also done by an "expert". All those things are what makes me a DIYer. Thanks again for all the perspectives.