Ultrasonic Cleaners

Does anyone have an ultrasonic cleaner that could advise? We have some budget left to possibly get one, and I'm wondering what sizes/capacity people would recommend shooting for. Also noticing a very large price and capacity disparity between the usual suppliers and what is available on Amazon. Typical 3Ltr is going for £500 on the likes of Breckland and Philip Harris, but a 10Ltr one is available on Amazon for £109. I'm unsure what to go with.
I've got a small ultrasonics bath from Ultrasonics Ltd. which is part of DAWE Instruments. Don't know how old it is, but it seems OK. I used to use one about x3 the size in industry, can't remember what the make was, but also seemed OK. I suppose it depends on what you'll use it for, whether to get a smaller or larger one, but personally I'd tend to go for the larger one as they should all reach a minimum standard.
Thanks for the input. I think considering the huge price gulf I'll get one of the larger ones from Amazon provided the budget can stretch to it and hope it's not a cheapo one that breaks instantly.