I spent a few days with the HX400, my conclusions are as follows
The HX400 is quite a nice superzoom camera, comfy in the hands and with good handling.
Unfortunately though, whilst the image quality is quite good at lower ISO levels, it takes a significant dive in less than ideal conditions. This reivew is to help you decide if the camera suits your needs (I raise some good and bad points that might not matter to you)
Sadly you are stuck with Sony's less than great jpeg engine, and it can't be overlooked that Sony have decided to deny users the chance to use raw processing (in 2014 this is a serious omission and all their rivals now offer this, and have done for some time)
The HX400 isn't a bad camera by any means, but the price is fairly steep and it falls short on the image quality front
My good and bad points:
+ Build is quite decent feels comfy in the hand with sensible and easy to learn controls
+ Useful 50x zoom (24-1200mm equivalent) starts at f2.8 dropping to f6.3 (ok speed wise for the range) it's quite good sharpness wise, not tack sharp at 24mm on the edges, but quite consistent across the range..it's still quite good at 1200mm too
+ Excellent 921k 3" rear LCD that is clear and sharp, not fully articulated (pull it out for overhead or low angle shooting) nice overall though
+ Mostly well featured, usual scene modes, manual mode, lots of filters, good macro ability, sweep panoramic mode: you can set the camera to remember your settings via 2 custom positions on the main mode dial.
+ Built in wifi, NFC and GPS, GPS locked on quite quickly too
+ EVF is quite good, clear and with a decent refresh rate, has eye sensor too. It's better than the Canon SX50 EVF, but not up to the FZ200 or HS50/XS-1
+ Metering and AF were both up to acceptable levels, exposures are mostly quite good (in lower light you might need to add some more exposure) AF was fairly fast across most of the range, drops off at the tele end (as they all do) It was on target more often that not, a bit above average performance here
+ Battery life is ok at about 330 shots, not class leading but not bad either
+ Video mode is quite good, full HD with stereo sound 25/50p supported too. Clarity was pretty good as was the sound; the AF did a decent job with holding focus even when zooming in and out quickly
+ Optical steadyshot works well around 3.5-4 stops, in line with other good IS systems
- No raw, for this class of camera it loses a star based purely on that
- Jpegs are ok at lower ISO levels, but run into overprocessing/strong noise reduction levels at anything over base ISO. At ISO 400 and up details are melted away leaving a painterly effect in images. Sharpening artefacts are also present in images due to poor jpeg processing
- Memory card slot at the bottom of the camera in the batery compartment, bit of a pain for tripod users
- Zoom motor can be heard in video mode (in quiet environments)
- Burst mode of 10fps can only shoot for about a second (common problem on bridge models) a bigger buffer would help a lot here
- Camera strap, rarely do I mention this but for a camera this price it's too narrow and uncomfortable
- High price
The camera is quite nice to use and I find it fits the hand well (it's quite similar to Sony's SLT models layout wise), grip is comfy and secure. I prefer a mechanical zoom, but the zoom controls here (on the side or around the shutter button) are quite good the zoom responds well and fairly smoothly to the touch controls.
The HX400v isn't a bad camera at all, it's just a shame that the jpegs are not better. They are reasonably detailed at the lower ISO settings, and satisfactory, but when light levels drop and high ISO speeds are used they are really not as good as they should be. The 20mp sensor might be more capable, but without raw we will never know. If the jpeg processing were better, I might add a star, sadly though this is a camera that really does need raw to get the best out of it.
If you don't pixel peep you might be ok with the Sony. I would shoot at half resolution myself, you're not getting any image quality advantage v other makers 12mp sensors. Maybe 20mp is too much to cram onto a small 1/2.3 inch sensor. Either way I have to be honest I think the HX400 is up for some stiff competition from other makers.
The HS50 has slightly less range, but also sports a decent EVF and LCD and has very fast AF in good light. The SX50 feels inferior to the Sony in handling and with a poor EVF and average LCD, but it does have image quality that is in my view better. FZ200 is also a solid choice with less range but a faster lens. Not to mention the XS-1 deals flying around right now.
All these cameras are quite a bit cheaper than the Sony, and deliver better image quality overall.
Had Sony improved their jpegs and put raw in here, and priced it at more realistic levels it could have been a contender for the one of the best superzooms out there. You have a nice body, good lens, hot shoe, good LCD and handling. It's a far nicer body to use than the Canon SX50, what a shame they didn't take the concept to it's natural conclusion. It should also be noted that you cannot in any way compare the image quality from a much larger APS-C image sensor, to the much smaller sensor in most bridge cameras. Image quality wise it's not even remotely close to a DSLR. This doesn't matter as bridge models can still take some fine images, and offer a flexbile all in one package (lens range) Just match your expectations accordingly
At a lower price it might be worth a look (also consider the previous HX300 model which offers better value, this isn't a huge update), right now I think you are better served looking at alternatives, and there are plenty of choices in this segment.