I've long used Bosch angle grinders because they are well made (usually Swiss-made by Scintilla AG), you have a fighting chance of repairing them (spare parts are available) and their smaller grinders still accept 'proper' wheels with the large centre bore and M14 threaded spindle (which many other smaller grinders do not).
For at least two decades I have used three 'professional quality' Bosch angle grinders and they have been good. I've had to lubricate the gearboxes and one (which was mainly used for brushing) eventually suffered a failed tail bearing. Finally one motor burnt out. Each had done hundreds of hours of grinding, and some of them were bought used rather than new.
The professional quality grinders (e.g. Blue GWS models) have always had continuously rated motors, metal gearbox housing, and ball/roller bearings inside the gearbox which support the output shaft. The 'hobby' ( e.g. Green coloured PWS models) have at different times variously had motors of different ratings, polymer gearbox housings, and the output shaft in the gearbox has had a different bearing configuration; most often a main ball bearing (as per the GWS models) and a plain bearing instead of a small roller bearing.
I bought a PWS-700 115 about a year ago and it has a continuously rated motor (I think), a metal gearbox housing and a ball/plain bearing setup on the output shaft. So it is very similar to the GWS model apart from the plain bearing in the gearbox. I think this plain bearing is unlikely to cause problems in the short term and in the long term will only be a problem if I abuse the machine and I don't pay attention to regreasing the gearbox from time to time.
Although 115mm discs are specified for Bosch Grinders of this sort, I find that most 125mm dia discs (a very commonly available size) will fit and work OK in these machines, albeit they have very little clearance to the guard when the discs are brand new. 125mm discs are much better value than 115mm discs because the small increase in diameter gives them nearly twice the useful life for jobs like cutting etc.
PWS-700 115 is available in most of the big DIY sheds and typically costs £35-40 if you shop around (some places will price match). The GWS model costs about £20 more than this; if it were another £10 I'd spring for the GWS but where I'd steered clear of PWS models (with plastic gearbox housings) in the past I have been happy so far with the one I bought, thus far. It is early days though; in another fifteen years I shall be able to tell you if it really was any good or not.
cheers
