Thanks for the replies. I've tries 22 and it seems fine enough although there is a slight lag when playing audio from memory. I'm only interested in audio and to be honest i can't tell between 17 & 22 as far as quality goes. Am i right in thinking that from 19 onwards there is increased ram usage? This would benefit more powerful machines? As i said before i had real problems with 19 and interupted audio when playing from memory and 22 seems more responsive with this feature turned off.
Going from 17 to 19 the playing from memory was drastically changed. It went from loading the compressed data (flac) to loading the uncompressed data (like wav) and this took a lot more memory and more CPU time whenever more data needed to be loaded into memory, since it needed to be decompressed. This basically broke Play from Memory for many people. That seems like what you ran into. If you do not use play from memory, going from 17 to 19 (or 22) should not cause any stuttering.
In 22, there is a new option called Load Files to Memory at Start of Playback, which essentially loads an entire compressed track into memory at the start of a track. To avoid stuttering at startup it does not play anything until the file is fully loaded. You need to uncheck Play Files from Memory for this new option to work. The new Load Files to Memory should be very fast, although there can be a delay if your file is on a USB drive that needs to be woken up or if a NAS or network drive needs to be accessed. There can also be a delay if your track is very long. This can be the case, for example, for a hi rez (196/24 or DSD) track of a symphony. The delay your report is probably the track being fully loaded into memory. But, if you do not delay the start of playback, you can get stuttering as the long file loads. If you turn off the Load Files to Memory option, there should be no delay.
I do not believe the basic audio engine has changed since 17, other than Play from Memory. Many features like more DSD support, the new Sox resampler, more DSP options, etc. have been added. But if you do not use any DSP options, the sound should be basically the same from 17 to 19. And Play from Memory worked well in 17.