if I buy an ultrasonic cleaner for my records will I be able to hear the difference?

I've heard of "clubs" forming to purchase and share the high end cleaners.  You pool your money, purchase the unit, and each "member" uses it for a week/month then sends it to the next person.

No question it will work. I bought the cleaner vinyl adapter and ultrasonic cleaner about 6 months ago...cleaned all of my several hundred records. It made a notable difference.  They play much quieter, surface noise was greatly reduced. I figure I spent about 300 for the adapter (2 record version) plus ultrasonic unit.  I used a very small amount of Dawn plus photo flo in distilled water.

My first record cleaning machine was KAB's version of the Nitty Gritty. When my friend bought a Keith Monks machine he gave me (!) his VPI 16.5. I have cleaned records using all three of these and have found that when used properly there is no difference in sound between them. All produced clean, quiet records. If you purchase a lot of cruddy used vinyl, an ultrasonic unit just might be better. The more money you spend, the more the machine will do for you.  

YES.   US cleaning will not magically repair damaged discs, but will likely make the sonic damage less audible.

I previously used a Spin Clean and Nitty Gritty---essentially a 2 step version of the VPI process.  I was mostly happy with my results.  Then I spent time to research US theory, process and application.

Purchased a DIY US kit.   Chinese tank, Vinyl Stacker, Rushton's formula.

My results are much better.  Surfaces (including from previously cleaned LPs) are more quiet.  I hear better reproduction of transients and ambiance cues- the the small and subtle sounds that can be buried underneath even moderate surface noise.

Before US cleaning, I still heard a low level   shhhhhhh-wooosh sound on many LPs.  After US, just about all gone.  My take is that a microscopic layer of debris becomes bonded to the LP surface over time.  The layer is thick enough to blunt transients and cover the very low level background cues in the mix.  US cleaning removes this layer, uncovering all that is in the groove to hear.

My cost was about $500.   New Kirmuss machine is about $8-900 and is a self contained box.  Other one box solutions are more expensive.

I wonder what happened to user @inna? (He was a frequent poster here for a while). What does this have to do with your question? He sent me a somewhat noisy record he had a couple copies of, and was curious to know whether my cleaning methods would produce a better result. (I combine conventional vacuum cleaning with ultrasonic, using a point nozzle type vacuum machine- typically more expensive than a wand type). if @Inna is still around, he can comment for himself- my recollection, not surprising to me, is that he heard more information from the record, but it didn’t necessarily eliminate the noise.
FWIW, I have been able to reduce groove noise type distortion on some copies that I would have attributed to damage of the record, but it usually involves multiple cleanings, using something like AIVS No. 15, pure water rinsing, and ultrasonic --sometimes repeatedly. (And in some cases, the record IS damaged, and no amount of cleaning will help). This is almost always something that involves an older record that was not handled or played with audiophile care, circa the late ’60s or early ’70s.
There’s a ton of stuff here and elsewhere on the benefits of ultrasonic. I like it, but it is not the sole method I use for cleaning- and I find, as I’ve written at length (sorry, I don’t mean that to sound pompous- just people might get bored seeing me say the same thing repeatedly), that the different cleaning methods- manual cleaning fluid application and vacuum RCM plus ultrasonic --are complementary and synergistic in result.