In order to prevent thread drift i'll try and provide a concise and balanced view of the R22, hopefully those who have strong views on the R22 can create a new thread and avoid distracting from the Cabri on this one.
The R22, like its big brothers is a very mechanically reliable aircraft. If it is flown within its limits and maintained properly, you are extremely unlikely to have any kind of mechanical issues that would be anything other than an inconvenience. Although, never designed as a training helicopter the R22 has been conducting large volumes of flight training all around the world since the 1980's and is still the primary training helicopter today, primarily on account of its low cost and reliability. The R22 was designed to the airworthiness standards that were in force in the 70's and these standards have been significantly upgraded since that time.
The R22 is a two-bladed helicopter and as in common with all two bladed helicopters from other manufacturers can suffer from mast-bumping accidents if flown into low-g conditions for whatever reason they occur. If you choose to fly in a 2-bladed helicopter you must understand these risks (or your EXPERIENCED instructor should) and manage them cautiously, this is not a difficult thing to do.
The R22 has a low inertia rotor system, which means that rotor RPM is quick to bleed off following a power failure if the pilot does not lower the collective immediately and execute a gentle cyclic flare. In high speed forward flight if the rotor speed suddenly decays the rotor will tend to tilt aft and if not corrected can contact the tail boom and cause a mid-air break up and/or mast bumping. (All rotors will behave like this but two blade helicopters can mast bump as a result and in low-inertia systems it all happens much quicker).
The low inertia of the R22 rotor also means that there is limited energy stored in the rotor to execute the final cushioning of an autorotative touchdown, this is by no means a difficult manoeuvre but will certainly focus your mind and it is important that you fly the right profile and manage your energy correctly. Again a good, experienced instructor is essential.
The general flight dynamics of the R22 are such that it is twitchy to fly. It has sensitive controls which take a little while to master, but once you have they will set you up very well to fly most other aircraft.
The R22 is relatively underpowered, for two reasons. Firstly, it derives its power de-rated, heavy Lycoming aircraft engine which has very limited hot and high performance (Beta model, the Beta 2 is better) and as designed has a very low power-to-weight ratio to allow the smallest most efficient engine to be used. This is compounded by the fact that you are almost always flying around close to maximum gross weight and the AUM of the R22 is only 1370lb/622kg. Flying one solo for the first time is a real eye opener! Being underpowered in a training helicopter is a mixed blessing, it removes one of the major margins your instructor has to get you out of trouble if you botch something, but it does teach you to make the best use of available power and keeps you very clearly focused on factors that can reduce your performance.
The R22 has manual carb heat, which means you have to manually monitor a gauge and ensure that the engine air inlet doesn't ice up and stop it running. All R22 Bets 2's have carb heat assist which correlates the carb heat control with collective movement which provide some protection, but it still needs constant monitoring. It is fair to say that carb icing has caused a number of problems over the years and is something you need to be very careful with if you fly R22 or R44R1. The onset of carb icing can be hidden by the rotor speed governor which compensates for the drooping RPM by opening the throttle until the engine is at full throttle and RPM is pulled down.
As I mentioned earlier the R22 was designed to a much older airworthiness code and doesn't provide very much crash protection at all by modern standards. There is some protection from crushable seat structures and landing gear deformation if the impact is vertically downwards...but not much else.
I think those are the main points.
In shortly, a well maintained and properly operated R22 coupled with an experienced R22 instructor is not a reckless choice by any means. You can never take your eye of the ball in any helicopter particularly the R22, but you can safely complete your PPL(H)/CPL(H) in it and many people have done and will continue to. If you only intend to fly recreationally, then make sure you fly regularly. The biggest problem with PPL's is how easy it is to forget important things through lack of regular flying.
The R22 is of its time, its 1970's technology. The G2 is 00's technology (except the engine) and as such benefits from all that we have learned in the intervening three decades - including the lessons learn from Robinson. It is much more benign in every sense, MUCH more crash worthy and much more failure tolerant. It uses the same old engine, so doesn't have any significant performance improvements over the R22, but that doesn't really matter for flying round in circles during training. However, these things come at a price and ultimately the decision will come down to whether you can afford it. The most important thing with R22's is make sure you get a good instructor, not a newbie with a few hundred hours.
I don't fly the R22 any more, but this is mainly on account of its size and speed - when I'm flying, I'm allways going somewhere. If I could get some bags into it, two people and cruise at 105kts then I probably would every time I didn't need the 44's extra seats. That said, I much prefer the autorotative characteristics of the R44, the hydraulic controls and it has bags of power when you're 2-up with bags and full fuel.
Hope this helps.
CRAN