I am in a similar sort of quandary. I currently use a GF S40 and have really had to learn how to get the best from it. I am now quite confident using it. However now I am, like you, looking for another system as I want to make bigger batches of beer. I have been doing a bit of product review and specification research and to be fair it appears to me that it does not matter much which bit of kit you buy they all suffer the same problem and this is that the mashing temperature is very difficult to control. Now I am not dismissing a new system at the moment but it seems to me reading user reviews that if I do buy another system I am just getting into another learning how to control it situation. I am certain there will be many upsides to a new system but the downsides look to be exactly the same, erratic mash temperatures. It is not difficult to understand why this happens the temperature probe in the kettle gets wort passed over it that is not representitve of what is actually happening up above in the mashing grain bed. I was watching a marketing video for the Brewzilla gen 4 65L and was really taken by it. I then looked for reviews of the kit by users and the reality is not anything like the marketing blurb. If I was being fair I would say that things like bluetooth and wifi connections are just marketing frills because the machine does not do what they say is will and that is maintain the temperature profile that you have programmed with any fidelity. If you think about it consistent mashing is a very important fundimental of brewing and it is the one thing that all the AIO systems fail badly at achieving.I'm looking for suggestions to help choose between (probably) these systems:
Brewzilla 35l gen4 (£410)
Brauheld Pro 45l (Klarstein £490)
Brauheld Smart 45l (Klarstein £375)
Unless there's any better suggestions, in the same price range.
The brewzilla includes a 13 loop Chiller coil.
Klarstein Chiller 12 cooling coil, listed as "Chiller 9" on their site, (21.5 cm diameter spiral with 18 cooling loops) adds an extra £70.
I'm mostly doing 23l batches, so the Brauheld extra 10l would only help with the occasional big beers. But can manage these, with care, in (friends) Brewzilla 35l (gen3), and guess gen 4 similar.
Did look at Bulldog Master Brewer 30l £585 inc immersion Chiller. Seems very like the Brauheld Pro 35l, but with twin wall construction. I think it's 30l size is too small for me. Shame as I like the twin wall, and getting a chiller complete with push-fit hose fittings.
Brewzilla: The domed bottom of the new gen brewzilla looks a great idea, to allow complete emptying via pump, without any tipping. And brewzilla spares seem widely available.
Brauheld: Don't see spares listed anywhere, and Klarstein seems to list very few spares for any products. Their Facebook page has many complaining of lack of parts / service.
Both Brauleld's: Have anti-burn circulation - optional pump recirculation via 2nd valve near bottom. With brewzilla gen3, this feature might have reduced temperature cycling a bit, but not sure if it's a big plus point. Bazooka screen filter (optional, on pump inlet?) is reported to require a raised inlet level, giving more incomplete emptying.
Brauheld Pro 45l: has pump housed in external box, with inlet coming from hose, with a push connector that goes on drain tap. So you can pump sparge water, by connecting this hose to the sparge vessel (or dipping extended hose in).
Review of (the similar Bulldog Master Brewer), said that the external pump was far superior to (previous Bulldog) internal one.
Brauheld Smart 45l: Has external sight tube. Not sure I'd ever use its smart connectivity (phone app).
With that in mind if I were you I would try to buy a system that primaraly is built well and resign myself to learning how to perfect your mashings because the marketing of even the best AIO is a promise that is not really achievable in the real world in my opinion.