I have only heard the clear audio concept, their entry level table. I found it dark and analytical. Of course some people love them. Lucky we have a lot of companies to choose from to meet our preferences.
I would definitely listen to everything you can before putting your cash down. Prime's do come up for sale used but they are so new that there not for sale all the time. I did find a crazy deal on a barely used one. Best advice is to be on top of the audio sites and be ready to pull the trigger quick on a good deal. You can save yourself a lot of money. Use pay pal and only buy from people with very positive transactions and its hard to go wrong. Worth the risk IMO.
There are some pretty good deals on Well Tempered Labs table on the net right now. I have not heard them but the prices are pretty good on the two I have seen. They don't seem to sell as quick as the used VPI tables. I would be surprised if you spent 4k on Table and you were not happy.
Upside with the Prime are as follow: sounds great, very good support thru VPI Forum users and VPI, Holds value and easy to sell, looks nice, Repair and support is in the US, upgrades are available.
Downside: They sound great with a pretty average setup up, but you can get them to sound MUCH better with a good setup. I can liteterally play trashed records and they sound almost dead quite once I got azimuth dialed in. You really can go down a rabbit hole to get these tables sounding there best, but again it really sounded quite good with a pretty quick setup. I will probblay go down the raibbit hole in the future because I think its worth it.
Best of luck.