We're used to products being updated, but with some it begs the question whether it's worth the upgrade or, perhaps, looking at grabbing a bargain and buying the older-generation product on a deal. So how does the just-announced Fujifilm X-T2 compact system camera differ from its X-T1 predecessor?

At first glance the two cameras look relatively similar, embodying a DSLR-style water-resistant design. The X-T2, however, has much larger and taller ISO, shutter speed and exposure compensation dials. The former two dials also have press-to-lock/release switches, rather than press-and-hold dials. However, the toggles to adjust drive mode and metering are rather fiddly in the new arrangement.

A key new addition for the X-T2 is dual SD card slots, both of which are UHS-II compatible for super-fast write speeds.

READ: Fujifilm X-T2 hands-on preview: Continuous autofocus to take-down pro DSLRs?

On the rear the X-T2 adds a new thumbtack control for adjusting focus point position, a feature absent on the X-T1, but pulled directly from the X-Pro2's layout.

While the X-T1 offers a tilt-angle LCD screen, the X-T2 enhances this to a three-way bracket. Via a button on the side of the camera the new screen can be tilted 90-degrees to the right for waist-level portrait-orientation work. It's clever, but we think a vari-angle or ball-and-socket arrangement (like the Pentax K-1) would be altogether more intelligent.

The screens of both cameras are 3-inches in size and have the same 1,040K-dot resolution. Neither are touchscreen, frustratingly.

Both cameras have the same resolution viewfinder, delivered via a 2.36m-dot OLED panel and huge 0.77x magnification. However, the X-T2's is 500nits, which is twice as bright as the X-T1's. Fujifilm also claims one stop better visual quality in low-light and 25 per cent better picture quality when focusing (although we can't grasp why the latter would be the case). The X-T2 also has a larger eyecup for better concealment.

But the biggest difference is refresh rate. The X-T1's 54fps has been upped to 60fps in the X-T2, but a Boost mode pushes that to 100fps for far smoother real-time results to the eye. Boost mode is activated using the down button on the d-pad, but eats away at battery power more considerably - hence not being activated by default.

Here's where things get rather interesting: the X-T2 has continuous autofocus that is potentially some six times more capable than the X-T1. But you'll need the optional VPB-XT2 vertical power booster grip to make the very most out of it.

As an example, Fujifilm demonstrated how the boost in processing, reduced shooting interval, blackout time and shutter time-lag would free-up more time in a 3fps burst to allow six opportunities to refocus in the X-T2, compared to the X-T1's one opportunity (because of slower processing, and longer interval/blackout/lag times).

As the burst speed increases the number of opportunities for refocus to be possible within a burst are reduced, but Fujifilm still cites that 5fps on the X-T2 is twice as capable as in the X-T1. We're talking accuracy here, as the system has those additional opportunities to refocus on a moving subject.

There are also scenario settings, with adjustment for tracking sensitivity, speed tracking sensitivity and zone area switching - the kind of controls found in much higher-end DSLR cameras, really. There are five presets (which can be adjusted) and one custom setting.

The VPB-XT2 vertical power booster grip can also be used to enhance continuous autofocus to 11 frames per second (11fps), if Boost mode is activated.

Without the grip the X-T2 can shoot 5fps, or 8fps with the Boost mode activated. The X-T1 could shoot at 8fps as standard.

Pulling the same sensor from the X-Pro2, the X-T2's 24-megapixel X-Trans CMOS III sensor is a big jump from the X-T1's 16-megapixel X-Trans CMOS II sensor.

Furthermore the X-T2's on-sensor phase detection area has increased to 75 per cent vertical and 50 per cent horizontal, for a wider active focus area. That's a big increase from the 40 per cent in both directions on the X-T1.

This new sensor also sees the X-T2 as Fujifilm's most capable video camera to date. Despite the removal of the one-touch movie button, the camera can capture 4K footage at up to 30fps (25/24p also available) with full F-Log Gamma options included. If you're in a hurry than the company's own Quick 4K means the on-board Film Simulation modes can be used for quick grading in-camera, without the need to post process. There's also 1080p capture up to 60fps (this is where the X-T1 maxed out), 4:2:2 HDMI out for off-camera recording, plus 3.5mm headphone and microphone jacks.

Here's the one part of the equation we don't yet know: price. The X-T1 was £1,049 body-only when it first launched, but costs around £849 at the time of writing. We're hopeful the X-T2 will be similarly priced (guesstimate £1,099?), and suspect a lot of additional cost will come from the VPB-XT2 grip (guesstimate £399 with both batteries). It will launch in September.

READ: Fujifilm X-T2 hands-on preview: Continuous autofocus to take-down pro DSLRs?