Opinion of budget phono preamps?

If you are going to change your whole preamp, there are a lot of good phono stages in some pre's. Far better than the rotel, creek, etc. That is definitely the best value for the money in that price range (the stuff you mentioned). Outboards become a better value when you have already invested money, or time, into a line stage and you want to upgrade one or the other without having to buy both, or switch both.
You are on the right track. While some of the pre's you mentioned might be questionable, as far as your taste and what you expect, as blw states, these budget phono's were meant to get your records going, and they are what they are. The real bargain would be found in obtaining phono's that were really made to get you farther than that.

One advantage of an outboard is you can park it close to you table and skip the ic's from table to phono, but keep in mind you may want to keep some space if the phono you get has it's power supply in the box as opposed to outboard.