ALL of the cheapie 3DPrinters are a compromise, but I can tell you from personal experience that the acrylic frame design is not a "does not hold up well" problem; it is a "breaks while you're building it and costs you lots of assache and delay" problem. Seriously: RUN, DO NOT WALK in the opposite direction.
The Tarantula was my 2nd machine; I can recommend it as an entry-level unit. Next step up is the Geeetech or the FolgerTech, depending on which architecture you prefer. All are Prusa i3 based. The "Wobble issue" is greatly overblown and directly related to how carefully you build. Arm guide wear is "armchair QB" hooey; IRL it holds up well over time. The aluminum upgrade kit has a version with all the hardware to easily add a second Z-axis stepper, or you can do it yourself with generic stepper motor mounts or make duplicates of the existing plates yourself.
Strengths of the Tarantula are: works out of the box (unless you get duff electronics; these are all made of the cheapest generic 3DP parts available) solid frame, very fine resolution for the price point, uses real leadscrew on the z-axis,
200 x 200 x 280 build volume for dirt cheap and most of all,
a solid base design that is easily upgraded in cheap increments.
Weaknesses are: Single rail on Y-axis works, can be fiddly but is easily and cheaply upgradable. Getting/keeping frame square can be fiddly, you have to be willing to drill/tap some end screws and add some 20¢ angles; recommended as part of initial build. Getting carriage square can be fiddly ( I believe this is entirely dependent on getting main frame built square first); I had zero problem with mine first try, but others reported unable to get tight & square and breaking acrylic carriage parts as a result.
Given the cost, I feel I did well. If I'd had a little more money at the outset, I'd have gone with the FolgerTech base 4020 model or the GeeeTech all-Aluminum model with LCD, or one of their middle-range models if I had a little more money still.
When I was shopping them, the GeeeTech used threaded rod instead of leadscrews; not sure if this is still the case. It's great strength is that ALL axes are built in relation to one single piece of flat plate; if that plate arrives perfectly flat, it's hard NOT to get a perfectly square build. If not... well, you can spend forever trying to get it right. This geometry is what the acrylic designs try to capitalize on, but you'd have to build out of 1/2" sheet to get the rigidity and strength you really need.
The FolgerTech has a little better hardware for a little more money, is dual Z-stepper and dual Y-axis rails out of the box, but of course you have to assemble a 4020 frame and get it perfectly square, just like the Tarantula.
The current version Large-volume Tarantula appears to come with the same capacitive proximity sensor for auto-leveling I added to mine; it also appears to have a better head and Bowden drive.
If I had room for a 2nd unit, I'd still consider another one over the FolgerTech & GeeeTech simply due to cost.The Wanhao has a lot of fanatical users, but it is known to have bed leveling inconsistency issues inherent in the design. The frame is sturdy enough to stand on, but it is easy to build a parallelogram instead of a cube if the machine stamping the holes cocks up. Yes, this is a thing with these. And of course, it costs considerably more than the above entry level machines for a very small build volume.
Cheers,
mnem
*Reflecting deeply on my pants*