I wanted to like the Cruiser Mk IV very much. I very much enjoyed its immediate predecessor, the Cruiser Mk III, which I ended up retaining. Indeed, there is a lot to like about the Cruiser Mk IV, as in many ways it is an improved version of the tank that came before. However, despite this I found myself disliking the gun selection, which rather detracted from the entire experience.
One noticeable thing about the Cruiser Mk IV is, once its engine is upgraded, is that it is quite a bit nippier than the earlier tank. While its top speed is technically the same, in reality the increased acceleration means that this vehicle is actually able to reach those higher speeds much more frequently. While not the fastest tank on a Tier III battlefield – that accolade now rests with the Panzer I Ausf. C which has dethroned the BT-7 – it will outpace the vast majority of enemy tanks. Likewise both the BT-7 and Panzer IC are rather more nimble than the Cruiser Mk IV. Do not think you are their equal in speed or agility, because if you do it will likely end poorly. That said you do have the necessary mobility to disrupt them. You do also very much have the velocity to find yourself too far ahead of your team-mates with the result of an early death.
The matter I find difficult with this tank is the armament. The top gun is the QF 40mm Mk IV autocannon, which fires two shells in one firing, and needs to be reloaded after two firings. The shells fire one after each other, with recoil between the two. Unfortunately the recoil often means that the second shot misses – one can try to depress the gun as firing to increase the chance of the second shell hitting the target, but it is an art I have very uneven success with. The reload time is lengthy for Tier III, but not obscene like the Panzer II Ausf. G.
The thing is I just have not really had much success with this gun. Part of me strongly prefers the initial QF 2pdr Mk IX. This single-shot weapon has a high rate of fire (if not quite as high as the autocannon), roughly the same penetration, and about 10% less damage. Theoretically the autocannon can put out an impressive about of dps, far more than the 2pdr. Given general play, and the large number of second-shell misses that seem to occur, I would wager the 2pdr causes more damage in most circumstances.
In Tier III matches you can essentially pretend you are a medium tank, but once a large number of Tier IVs roll into view it is time to re-assess. This tank has good speed, and view range, so can make a quite creditable scout. It also has pretty depression on its weapons, which means it can be effective use of terrain when trying to harass other vehicles. Do be aware however than in general that you cannot do much against the Tier V heavies, and the better all-around armour of the KV-1 makes that one practically invulnerable from you. The best you can do is try to track it and let your team-mates deal with it. Most other Tier V tanks can be flanked, if not entirely reliably.
My final tally with the Cruiser MK IV is sixteen battles, seven victories, and thirteen enemy kills. I did manage to secure a Scout medal and a Confederate medal in one particularly memorable match, in which I also earned the First Class Mastery Badge. Despite that match showing just what this tank can do I have to desire to keep this tank in my garage, and it will be moving out in due course.